Haɓaka babban aiki, šaukuwa da ƙananan na'urori masu auna iskar gas yana samun ƙarin kulawa a fagagen sa ido kan muhalli, tsaro, binciken likita da aikin gona.Daga cikin kayan aikin gano daban-daban, ƙarfe-oxide-semiconductor (MOS) na'urori masu auna iskar gas na chemo-resistive gas sune mafi mashahuri zaɓi don aikace-aikacen kasuwanci saboda girman kwanciyar hankali, ƙarancin farashi, da hankali mai girma.Ɗaya daga cikin mahimman hanyoyin da za a kara inganta aikin firikwensin shine ƙirƙirar nanosized MOS-based heterojunctions (hetero-nanostructured MOS) daga MOS nanomaterials.Duk da haka, tsarin ji na na'urar firikwensin MOS mai heteronanostructured ya bambanta da na firikwensin gas na MOS guda ɗaya, saboda yana da wuyar gaske.Ayyukan firikwensin yana shafar sigogi daban-daban, gami da kaddarorin jiki da sinadarai na abu mai mahimmanci (kamar girman hatsi, ƙarancin lahani, da guraben kayan oxygen), zafin aiki, da tsarin na'ura.Wannan bita yana gabatar da ra'ayoyi da yawa don ƙira manyan na'urori masu auna iskar gas ta hanyar nazarin tsarin ji na na'urori masu auna siginar MOS.Bugu da ƙari, an tattauna tasirin tsarin geometric na na'urar, wanda aka ƙaddara ta hanyar dangantaka tsakanin abu mai mahimmanci da lantarki mai aiki.Don nazarin halayen firikwensin tsari, wannan labarin yana gabatarwa da kuma tattauna tsarin gaba ɗaya na hasashe na nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan na'urori ne da wannan labarin ke gabatarwa.Wannan bayyani zai zama jagora ga masu karatu na gaba waɗanda ke nazarin hanyoyin kula da na'urori masu auna iskar gas da haɓaka manyan firikwensin gas.
Gurbacewar iska matsala ce da ke kara tsananta kuma babbar matsalar muhalli ta duniya da ke barazana ga rayuwar mutane da masu rai.Shakar gurbatacciyar iska na iya haifar da matsalolin lafiya da yawa kamar cututtukan numfashi, ciwon huhu, cutar sankarar bargo da ma mutuwa da wuri1,2,3,4.Daga shekarar 2012 zuwa 2016, an bayar da rahoton cewa miliyoyin mutane sun mutu sakamakon gurbacewar iska, kuma a kowace shekara, biliyoyin mutane na fuskantar rashin ingancin iska5.Sabili da haka, yana da mahimmanci don haɓaka na'urori masu ɗaukar nauyi da ƙananan na'urorin gas waɗanda za su iya ba da amsa na ainihi da babban aikin ganowa (misali, hankali, zaɓi, kwanciyar hankali, da amsawa da lokutan dawowa).Baya ga kula da muhalli, na'urori masu auna iskar gas suna taka muhimmiyar rawa a cikin aminci6,7,8, likitancin likita9,10, aquaculture11 da sauran fannoni12.
Ya zuwa yau, an gabatar da na'urori masu ɗaukan iskar gas da yawa dangane da hanyoyin ganowa daban-daban, irin su optic13,14,15,16,17,18, electrochemical19,20,21,22 da na'urori masu tsayayya da sinadarai23,24.Daga cikin su, ƙarfe-oxide-semiconductor (MOS) na'urori masu tsayayyar sinadarai sun fi shahara a aikace-aikacen kasuwanci saboda girman kwanciyar hankali da ƙarancin farashi25,26.Ana iya ƙayyade ƙaddamarwar gurɓataccen abu kawai ta hanyar gano canji a cikin juriya na MOS.A farkon shekarun 1960, an ba da rahoton na'urori masu auna iskar gas na chemo-resistive na farko dangane da finafinan bakin ciki na ZnO, wanda ya haifar da babbar sha'awa a fagen gano iskar gas27,28.A yau, ana amfani da MOS daban-daban a matsayin kayan da ke da iskar gas, kuma ana iya raba su zuwa kashi biyu bisa ga kaddarorinsu na jiki: n-type MOS tare da electrons a matsayin mafi yawan masu cajin da kuma p-type MOS tare da ramuka a matsayin mafi yawan masu caji.masu caji.Gabaɗaya, nau'in p-type MOS ba shi da mashahuri fiye da nau'in MOS na n-type saboda amsawar amsawar nau'in p-type MOS (Sp) daidai yake da tushen murabba'in nau'in n-type MOS (S_p = \sqrt { S_n}\ ) ) a cikin zato guda ɗaya (misali, tsarin halittar jiki iri ɗaya da kuma canji iri ɗaya a cikin lanƙwasa makaɗa a cikin iska) 29,30.Koyaya, na'urori masu auna firikwensin MOS guda ɗaya har yanzu suna fuskantar matsaloli kamar ƙarancin ganowa, ƙarancin hankali da zaɓi a aikace-aikace masu amfani.Za a iya magance batutuwan zaɓin har zuwa wani lokaci ta hanyar samar da tsararrun na'urori masu auna firikwensin (wanda ake kira "electronic noses") da kuma haɗa algorithms bincike na lissafi irin su horar da ƙididdige ƙididdiga (LVQ), principal component analysis (PCA), da ƙananan ƙananan murabba'ai (PLS) analysis31 , 32, 33, 34, 35. Bugu da kari, da samar da low-girma MOS32,36,37,38,39 (misali daya-girma (1D), 0D da 2D nanomaterials), kazalika da amfani da sauran nanomaterials ( misali MOS40,41,42 , Noble karfe nanoparticles (NPs)) 43,44, carbon nanomaterials45,46 da conductive polymers47,48) don ƙirƙirar nanoscale heterojunctions (watau, heteronostructured MOS) wasu fi so hanyoyin da za a warware a sama matsaloli.Idan aka kwatanta da fina-finan MOS masu kauri na gargajiya, MOS mai ƙarancin girma tare da takamaiman yanki na musamman na iya samar da ƙarin wuraren aiki don tallan iskar gas da sauƙaƙe yaduwar iskar gas36,37,49.Bugu da ƙari, ƙirar ƙirar heteronostructures na MOS na iya ƙara haɓaka jigilar jigilar kaya a heterointerface, yana haifar da manyan canje-canje a cikin juriya saboda ayyuka daban-daban na aiki50,51,52.Bugu da ƙari, wasu tasirin sinadarai (misali, aikin catalytic da halayen haɗin gwiwar haɗin kai) waɗanda ke faruwa a cikin ƙirar MOS heteronanostructures kuma na iya inganta aikin firikwensin .50,53,54 Ko da yake ƙirƙira da ƙirƙira MOS heteronanostructures zai zama wata hanya mai ban sha'awa don ingantawa. Ayyukan firikwensin, na'urori masu juriya na chemo na zamani yawanci suna amfani da gwaji da kuskure, wanda ke ɗaukar lokaci kuma mara inganci.Sabili da haka, yana da mahimmanci a fahimci tsarin ji na na'urori masu auna iskar gas na MOS kamar yadda zai iya jagorantar ƙira na manyan firikwensin kwatance.
A cikin 'yan shekarun nan, MOS gas na'urori masu auna sigina sun ci gaba da sauri kuma an buga wasu rahotanni akan MOS nanostructures55,56,57, dakin zafin jiki gas na'urorin 58,59, MOS firikwensin kayan aiki60,61,62 da kuma na'urorin gas na musamman63.Takardar bita a cikin Sauran Bita na mayar da hankali kan ƙaddamar da tsarin ji na na'urori masu auna iskar gas dangane da abubuwan da ke cikin jiki da na sinadarai na MOS, ciki har da rawar da ake yi na oxygen 64 , rawar heteronanostructures 55, 65 da canja wurin cajin a heterointerfaces 66. Bugu da ƙari. , da yawa wasu sigogi shafi firikwensin yi, ciki har da heterostructure, hatsi size, aiki zafin jiki, lahani yawa, oxygen vacances, har ma da bude crystal jirage na m abu25,67,68,69,70,71.72, 73. Duk da haka, tsarin (ba a ambata ba) tsarin geometric na na'urar, wanda aka ƙaddara ta hanyar dangantaka tsakanin kayan ji da kuma lantarki mai aiki, kuma yana tasiri mai mahimmanci na firikwensin74,75,76 (duba sashe na 3 don ƙarin cikakkun bayanai) .Misali, Kumar et al.77 ya ruwaito na'urori masu auna gas guda biyu dangane da abu ɗaya (misali, firikwensin gas mai Layer biyu dangane da TiO2@NiO da NiO@TiO2) kuma sun lura da canje-canje daban-daban a cikin juriyar gas na NH3 saboda nau'ikan geometries na na'ura.Sabili da haka, lokacin da ake nazarin tsarin iskar gas, yana da mahimmanci a la'akari da tsarin na'urar.A cikin wannan bita, marubutan sun mai da hankali kan hanyoyin gano tushen MOS don nau'ikan nanostructures iri-iri da tsarin na'ura.Mun yi imanin cewa wannan bita na iya zama jagora ga masu karatu da ke son fahimta da nazarin hanyoyin gano iskar gas kuma zai iya ba da gudummawa ga haɓaka manyan na'urori masu auna iskar gas na gaba.
A kan fig.1a yana nuna ainihin ƙirar ƙirar iskar gas dangane da MOS guda ɗaya.Yayin da zafin jiki ya tashi, ƙaddamar da kwayoyin oxygen (O2) a kan MOS surface zai jawo hankalin electrons daga MOS kuma ya samar da nau'in anionic (kamar O2- da O-).Sa'an nan kuma, an samar da Layer depletion Layer (EDL) don nau'in n-type MOS ko rami accumulation Layer (HAL) don nau'in p-type MOS a saman MOS 15, 23, 78. Mu'amala tsakanin O2 da MOS yana haifar da rukunin gudanarwa na MOS don tanƙwara sama kuma ya samar da wani shinge mai yuwuwa.Daga baya, lokacin da firikwensin ya fallasa ga iskar da aka yi niyya, iskar gas ɗin da aka yi a saman MOS tana amsawa tare da nau'in oxygen na ionic, ko dai yana jan hankalin electrons (gas oxidizing) ko ba da gudummawar electrons (rage gas).Canja wurin lantarki tsakanin iskar gas da MOS na iya daidaita nisa na EDL ko HAL30,81 wanda ke haifar da canji a cikin juriya na firikwensin MOS.Misali, don rage yawan iskar gas, za a canza electrons daga rage iskar gas zuwa nau'in MOS na n, wanda zai haifar da ƙaramin EDL da ƙananan juriya, wanda ake magana da shi azaman halayen firikwensin nau'in n.Sabanin haka, lokacin da MOS na nau'in p-type ya bayyana ga rage gas wanda ke ƙayyade halin halayen p-type, HAL yana raguwa kuma juriya yana ƙaruwa saboda gudummawar lantarki.Don iskar iskar oxygen, martanin firikwensin ya saba wa wancan don rage iskar gas.
Hanyoyin gano asali don nau'in n-nau'i da nau'in p-type MOS don ragewa da iskar gas b Mahimman abubuwa da physico-chemical ko kayan kayan da ke cikin na'urori masu auna firikwensin gas 89
Baya ga ainihin hanyar ganowa, hanyoyin gano iskar gas da ake amfani da su a cikin na'urori masu auna iskar gas suna da wahala sosai.Misali, ainihin amfani da firikwensin iskar gas dole ne ya cika buƙatu da yawa (kamar hankali, zaɓi, da kwanciyar hankali) dangane da buƙatun mai amfani.Waɗannan buƙatun suna da alaƙa da alaƙa ta zahiri da sinadarai na abu mai mahimmanci.Misali, Xu et al.71 ya nuna cewa na'urori masu auna firikwensin SnO2 sun sami mafi girman hankali lokacin da diamita crystal (d) daidai yake da ko ƙasa da sau biyu na tsawon Debye (λD) na SnO271.Lokacin d ≤ 2λD, SnO2 ya ƙare gaba ɗaya bayan tallan ƙwayoyin O2, kuma amsawar firikwensin ga rage yawan iskar gas shine matsakaicin.Bugu da kari, wasu sigogi daban-daban na iya shafar aikin firikwensin, gami da zafin aiki, lahani na kristal, har ma da fallasa jiragen kristal na kayan ji.Musamman ma, tasirin yanayin zafin aiki yana bayyana ta hanyar yuwuwar gasa tsakanin ƙimar adsorption da desorption na iskar gas, da kuma sake kunnawa ta sama tsakanin ƙwayoyin iskar gas da kuma ƙwayoyin iskar oxygen4,82.Tasirin lahani na crystal yana da alaƙa mai ƙarfi da abun ciki na guraben oxygen [83, 84].Hakanan ana iya shafar aikin firikwensin ta daban-daban reactivity na buɗe fuskokin crystal67,85,86,87.Buɗe jirage na crystal tare da ƙananan yawa suna bayyana ƙarin cations na ƙarfe mara daidaituwa tare da manyan kuzari, waɗanda ke haɓaka tallan saman ƙasa da reactivity88.Tebu na 1 ya lissafa abubuwa masu mahimmanci da yawa da ingantattun hanyoyin fahimta.Sabili da haka, ta hanyar daidaita waɗannan sigogi na kayan, ana iya inganta aikin ganowa, kuma yana da mahimmanci don ƙayyade mahimman abubuwan da ke shafar aikin firikwensin.
Yamazoe89 da Shimanoe et al.68,71 sun yi nazari da yawa game da tsarin ka'idar ka'idar hasashe na firikwensin kuma sun ba da shawarar abubuwa uku masu zaman kansu da ke tasiri aikin firikwensin, musamman aikin mai karɓa, aikin transducer, da mai amfani (Fig. 1b)..Ayyukan mai karɓa yana nufin iyawar saman MOS don yin hulɗa tare da kwayoyin gas.Wannan aikin yana da alaƙa da alaƙa da sinadarai na MOS kuma ana iya haɓakawa sosai ta hanyar gabatar da masu karɓar ƙasashen waje (misali, NPs na ƙarfe da sauran MOS).Ayyukan transducer yana nufin ikon canza amsawa tsakanin iskar gas da MOS a cikin siginar lantarki wanda ke mamaye iyakokin hatsi na MOS.Don haka, aikin azanci yana tasiri sosai ta hanyar girman barbashi na MOC da yawa na masu karɓa na waje.Katoch et al.90 ya ruwaito cewa rage girman hatsi na ZnO-SnO2 nanofibrils ya haifar da samuwar heterojunctions da yawa da kuma ƙara yawan firikwensin firikwensin, daidai da aikin transducer.Wang et al.91 idan aka kwatanta nau'o'in nau'in hatsi na Zn2GeO4 kuma sun nuna karuwa na 6.5 a cikin firikwensin firikwensin bayan gabatar da iyakokin hatsi.Utility wani maɓalli ne na aikin firikwensin firikwensin da ke bayyana kasancewar iskar gas zuwa tsarin MOS na ciki.Idan kwayoyin iskar gas ba za su iya shiga ba kuma su amsa tare da MOS na ciki, za a rage jin daɗin firikwensin.Amfanin yana da alaƙa da alaƙa da zurfin yaduwa na wani iskar gas, wanda ya dogara da girman pore na kayan ji.Sakai et al.92 ya ƙirƙira ƙwarewar firikwensin zuwa iskar gas kuma ya gano cewa duka nauyin kwayoyin gas da radius na radius na firikwensin firikwensin suna shafar hankalin firikwensin a zurfin yaduwar iskar gas daban-daban a cikin membrane na firikwensin.Tattaunawar da ke sama tana nuna cewa ana iya haɓaka na'urori masu auna iskar gas mai ƙarfi ta hanyar daidaitawa da haɓaka aikin mai karɓa, aikin transducer, da mai amfani.
Ayyukan da ke sama yana fayyace ainihin tsarin fahimtar MOS guda ɗaya kuma ya tattauna abubuwa da yawa waɗanda ke shafar aikin MOS.Baya ga waɗannan abubuwan, na'urori masu auna iskar gas dangane da heterostructures na iya ƙara haɓaka aikin firikwensin ta hanyar inganta firikwensin da ayyuka masu karɓa.Bugu da ƙari, heteronostructures na iya ƙara haɓaka aikin firikwensin ta hanyar haɓaka halayen haɓakawa, daidaita canjin caji, da ƙirƙirar ƙarin wuraren talla.Har zuwa yau, yawancin na'urori masu auna iskar gas bisa ga MOS heteronanostructures an yi nazarin su don tattauna hanyoyin inganta haɓakawa95,96,97.Miller et al.55 ya taƙaita hanyoyin da yawa waɗanda zasu iya inganta haɓakar halayen heteronostructures, ciki har da masu dogaro da ƙasa, masu dogaro da musaya, da tsarin dogaro.Daga cikin su, tsarin haɓakawa da ke dogara da mu'amala yana da wahala sosai don rufe duk hulɗar mu'amala a cikin ka'idar guda ɗaya, tunda ana iya amfani da na'urori daban-daban dangane da kayan da aka ƙera (misali, nn-heterojunction, pn-heterojunction, pp-heterojunction, da sauransu.) .Kullin Schottky).Yawanci, na'urorin firikwensin heteronostructured na tushen MOS ko da yaushe sun haɗa da na'urorin firikwensin ci gaba biyu ko fiye98,99,100.Tasirin haɗin kai na waɗannan hanyoyin haɓakawa na iya haɓaka liyafar da sarrafa siginar firikwensin.Don haka, fahimtar tsarin hangen nesa na na'urori masu auna firikwensin dangane da nau'ikan nau'ikan nau'ikan nau'ikan nanostructured yana da mahimmanci don taimakawa masu bincike haɓaka na'urori masu auna iskar gas daidai da bukatunsu.Bugu da kari, tsarin geometric na na'urar kuma na iya tasiri sosai kan ji na firikwensin 74, 75, 76. Don bincikar halayen firikwensin cikin tsari, za a gabatar da hanyoyin ji na tsarin na'urori guda uku dangane da kayan da aka gyara daban-daban na heteronanostructured. kuma tattauna a kasa.
Tare da saurin haɓakar na'urori masu auna iskar gas na MOS, an ba da shawarar MOS iri-iri iri-iri.Canja wurin cajin a heterointerface ya dogara da matakan Fermi daban-daban (Ef) na abubuwan haɗin gwiwa.A heterointerface, electrons suna motsawa daga gefe ɗaya tare da babban Ef zuwa wancan gefe tare da ƙaramin Ef har sai matakan Fermi ya kai ga daidaito, da ramuka, akasin haka.Sa'an nan kuma masu ɗaukar kaya a heterointerface sun ƙare kuma suna samar da wani nau'i mai lalacewa.Da zarar na'urar firikwensin ya fallasa ga iskar gas ɗin da aka yi niyya, ƙaddamarwar jigilar jigilar MOS heteronanostructured yana canzawa, kamar yadda tsayin shingen ke yi, ta haka yana haɓaka siginar ganowa.Bugu da ƙari, hanyoyi daban-daban na ƙirƙira heteronostructures suna haifar da dangantaka daban-daban tsakanin kayan aiki da na'urorin lantarki, wanda ke haifar da nau'o'in geometries na na'ura daban-daban da hanyoyin ganewa daban-daban.A cikin wannan bita, muna ba da shawarar tsarin na'urar geometric guda uku kuma mu tattauna tsarin ji na kowane tsari.
Ko da yake heterojunctions suna taka muhimmiyar rawa a aikin gano iskar gas, lissafin na'urar gabaɗayan firikwensin kuma na iya yin tasiri sosai akan halayen ganowa, tunda wurin tashar sarrafa firikwensin ya dogara sosai akan lissafin na'urar.An tattauna nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan MOS guda uku a nan, kamar yadda aka nuna a cikin Hoto 2. A cikin nau'in farko, ana rarraba haɗin MOS guda biyu ba tare da izini ba tsakanin na'urorin lantarki guda biyu, kuma wurin da tashar tashar ke ƙayyade ta babban MOS, na biyu shine. samuwar nau'ikan nanostructures daban-daban daga MOS daban-daban, yayin da MOS ɗaya kawai ke haɗa da lantarki.An haɗa na'urar lantarki, to, tashar tashar yawanci tana cikin MOS kuma an haɗa ta kai tsaye zuwa lantarki.A cikin nau'i na uku, an haɗa kayan biyu zuwa na'urorin lantarki guda biyu daban, suna jagorantar na'urar ta hanyar heterojunction da aka kafa tsakanin kayan biyu.
Sake tsakanin mahadi (misali "SnO2-NiO") yana nuna cewa an haɗa abubuwa biyu kawai (nau'in I).Alamar "@" tsakanin haɗin gwiwa guda biyu (misali "SnO2@NiO") yana nuna cewa an ƙawata kayan aikin (NiO) da SnO2 don tsarin firikwensin nau'in II.Slash (misali "NiO/SnO2") yana nuna ƙirar firikwensin nau'in III .
Don na'urori masu auna iskar gas dangane da abubuwan MOS, abubuwa biyu na MOS ana rarraba su ba da gangan ba tsakanin na'urorin lantarki.An haɓaka hanyoyin ƙirƙira da yawa don shirya abubuwan haɗin MOS, gami da sol-gel, coprecipitation, hydrothermal, electrospinning, da hanyoyin haɗaɗɗen inji98,102,103,104.Kwanan nan, tsarin ƙarfe-kwakwalwa (MOFs), wani nau'i na kayan gyare-gyare na porous crystalline wanda ya ƙunshi cibiyoyin ƙarfe da masu haɗin jiki, an yi amfani da su azaman samfuri don ƙirƙira na MOS composites105,106,107,108.Yana da kyau a lura cewa ko da yake yawan adadin MOS composites iri ɗaya ne, halayen halayen halayen na iya bambanta sosai lokacin amfani da tsarin masana'antu daban-daban. ( Mo: Sn = 1: 1.9) kuma sun gano cewa hanyoyin ƙirƙira daban-daban suna haifar da hankali daban-daban.Shaposhnik et al.110 ya ba da rahoton cewa amsawar SnO2-TiO2 da aka haɗa zuwa gaseous H2 ya bambanta da na kayan haɗaɗɗen injina, har ma da daidaitaccen Sn/Ti.Wannan bambanci ya taso saboda alakar dake tsakanin MOP da MOP crystallite size ya bambanta da hanyoyi daban-daban na kira109,110.Lokacin da girman nau'in hatsi da siffar ya kasance daidai dangane da ƙimar mai bayarwa da nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'in nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i) nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'i-nau'i-nau'i.Staerz et al.111 ya ruwaito cewa halayen ganowa na SnO2-Cr2O3 core-sheath (CSN) nanofibers da ƙasa SnO2-Cr2O3 CSN sun kasance kusan iri ɗaya, suna nuna cewa nanofiber ilimin halittar jiki ba ya ba da wani fa'ida.
Baya ga hanyoyin ƙirƙira daban-daban, nau'ikan semiconductor na MOSFET daban-daban guda biyu suma suna shafar hankalin firikwensin.Ana iya ƙara raba shi zuwa nau'i biyu dangane da ko MOSFET guda biyu na nau'in semiconductor iri ɗaya ne (nn ko pp junction) ko nau'ikan nau'ikan (pn junction).Lokacin da na'urori masu auna gas sun dogara ne akan abubuwan MOS na nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i) nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i) ta hanyar canza ma'auni na molar na MOS guda biyu.Lokacin da kashi ɗaya ya fi rinjaye a cikin abubuwan da aka haɗa (misali 0.9 ZnO-0.1 SnO2 ko 0.1 ZnO-0.9 SnO2), tashar gudanarwa ta ƙaddara ta MOS mai rinjaye, wanda ake kira tashar jigilar homojunction 92 .Lokacin da ma'auni na sassan biyu suka yi daidai, ana ɗauka cewa tashar gudanarwa ta mamaye heterojunction98,102.Yamazoe et al.112,113 ya ruwaito cewa yankin heterocontact na sassan biyu na iya inganta haɓakar firikwensin sosai saboda shingen heterojunction da aka kafa saboda ayyuka daban-daban na abubuwan da aka gyara na iya sarrafa sarrafa motsin firikwensin da aka fallasa ga electrons.Gas daban-daban na yanayi 112,113.A kan fig.Hoto 3a yana nuna cewa na'urori masu auna firikwensin da suka dogara da tsarin tsarin SnO2-ZnO fibrous tare da abubuwan ZnO daban-daban (daga 0 zuwa 10 mol% Zn) na iya zaɓar gano ethanol.Daga cikin su, firikwensin da ke kan SnO2-ZnO fibers (7 mol.% Zn) ya nuna mafi girman hankali saboda samuwar babban adadin heterojunctions da karuwa a cikin wani yanki na musamman, wanda ya kara yawan aikin mai canzawa kuma ya inganta. Hankali 90 Duk da haka, tare da ƙarin karuwa a cikin ZnO abun ciki zuwa 10 mol.%, microstructure SnO2-ZnO composite zai iya nannade wuraren kunnawa saman da kuma rage firikwensin hankali85.Hakanan ana lura da irin wannan yanayin don na'urori masu auna firikwensin dangane da NiO-NiFe2O4 pp heterojunction composites tare da ma'aunin Fe/Ni daban-daban (Fig. 3b)114.
Hotunan SEM na SnO2-ZnO fibers (7 mol.% Zn) da kuma amsawar firikwensin ga gas daban-daban tare da ƙaddamar da 100 ppm a 260 ° C;54b Martanin na'urori masu auna firikwensin dangane da tsarkakakken NiO da NiO-NiFe2O4 composites a 50 ppm na iskar gas daban-daban, 260 °C;114 (c) Tsarin tsari na adadin nodes a cikin xSnO2- (1-x) Co3O4 abun da ke ciki da kuma daidaitattun juriya da halayen halayen xSnO2- (1-x) Co3O4 abun da ke ciki ta 10 ppm CO, acetone, C6H6 da SO2 iskar gas a 350 °C ta canza ma'aunin molar na Sn/Co 98
Ƙungiyoyin pn-MOS suna nuna halaye na hankali daban-daban dangane da rabon atomic na MOS115.Gabaɗaya, halayen halayen MOS composites sun dogara sosai akan abin da MOS ke aiki azaman tashar gudanarwa ta farko don firikwensin.Sabili da haka, yana da matukar mahimmanci don siffanta adadin adadin da nanostructure na composites.Kim et al.98 sun tabbatar da wannan ƙarshe ta hanyar haɗa jerin xSnO2 ± (1-x) Co3O4 nanofibers masu haɗaka ta hanyar lantarki da kuma nazarin abubuwan firikwensin su.Sun lura cewa halin SnO2-Co3O4 mai haɗa firikwensin ya canza daga nau'in n-type zuwa nau'in p-type ta hanyar rage yawan SnO2 (Fig. 3c)98.Bugu da kari, na'urori masu auna firikwensin heterojunction (dangane da 0.5 SnO2-0.5 Co3O4) sun nuna mafi girman adadin watsawa don C6H6 idan aka kwatanta da na'urori masu auna firikwensin homojunction (misali, manyan SnO2 ko Co3O4 firikwensin).Babban juriya na asali na 0.5 SnO2-0.5 Co3O4 tushen firikwensin da mafi girman ikonsa don daidaita juriyar firikwensin gabaɗaya yana ba da gudummawa ga mafi girman hankali ga C6H6.Bugu da kari, lattice rashin daidaiton lahani wanda ya samo asali daga SnO2-Co3O4 heterointerfaces na iya ƙirƙirar wuraren tallan da aka fi so don ƙwayoyin iskar gas, don haka haɓaka amsawar firikwensin109,116.
Baya ga nau'in semiconductor MOS, ana iya daidaita halayen taɓawa na MOS composites ta amfani da sinadarai na MOS-117.Huo et al.117 ya yi amfani da hanyar soak-bake mai sauƙi don shirya abubuwan haɗin gwiwar Co3O4-SnO2 kuma sun gano cewa a cikin Co / Sn molar rabo na 10%, firikwensin ya nuna amsawar gano nau'in p-nau'in H2 da nau'in n-nau'in hankali ga H2.amsa.Ana nuna martanin firikwensin ga gas CO, H2S da NH3 a cikin Hoto 4a117.A ƙananan ƙananan Co / Sn, yawancin homojunctions suna samuwa a SnO2 ± SnO2 nanograin iyakoki da kuma nuna n-type firikwensin martani ga H2 (Figs. 4b, c) 115.Tare da karuwa a cikin rabon Co/Sn har zuwa 10 mol.%, maimakon SnO2-SnO2 homojunctions, yawancin Co3O4-SnO2 heterojunctions an kafa su lokaci guda (Fig. 4d).Tun da Co3O4 ba shi da aiki game da H2, kuma SnO2 yana amsawa da ƙarfi tare da H2, halayen H2 tare da nau'in oxygen na ionic yafi faruwa a saman SnO2117.Saboda haka, electrons suna matsawa zuwa SnO2 da Ef SnO2 suna canzawa zuwa bandejin gudanarwa, yayin da Ef Co3O4 ya kasance baya canzawa.A sakamakon haka, juriya na firikwensin yana ƙaruwa, yana nuna cewa kayan da ke da babban rabo na Co / Sn suna nuna halin p-type (Fig. 4e).Sabanin haka, CO, H2S, da NH3 gas suna amsawa tare da nau'in oxygen na ionic akan SnO2 da Co3O4 saman, kuma electrons suna motsawa daga gas zuwa firikwensin, wanda ya haifar da raguwa a tsayin shinge da kuma n-type sensitivity (Fig. 4f)..Wannan dabi'ar firikwensin daban-daban ya samo asali ne saboda amsawar Co3O4 daban-daban tare da iskar gas daban-daban, wanda Yin et al ya ƙara tabbatarwa.118 .Hakanan, Katoch et al.119 ya nuna cewa SnO2-ZnO composites suna da zaɓi mai kyau da babban hankali ga H2.Wannan dabi'a tana faruwa ne saboda ana iya haɗa kwayoyin H a cikin sauƙi zuwa wuraren O na ZnO saboda ƙaƙƙarfan haɓakawa tsakanin s-orbital na H da p-orbital na O, wanda ke haifar da haɓakar ZnO120,121.
a Co/Sn-10% tsayin juriya masu lankwasa don rage yawan iskar gas kamar H2, CO, NH3 da H2S, b, c Co3O4/SnO2 ƙirar ƙirar ƙirar ƙirar ƙira don H2 a ƙananan % m.Co/Sn, df Co3O4 Mechanism Ganewar H2 da CO, H2S da NH3 tare da babban Co/Sn/SnO2 composite
Sabili da haka, zamu iya inganta haɓakar firikwensin nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i-nau'i)) ta hanyar zabar hanyoyin ƙirƙira da suka dace, rage yawan ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar ƙwayar cuta ta MOS.Bugu da ƙari, zurfin fahimtar sinadarai na abu mai mahimmanci na iya ƙara haɓaka zaɓi na firikwensin.
Tsarin firikwensin Nau'in II wani sanannen tsarin firikwensin firikwensin da zai iya amfani da nau'ikan nanostructured iri-iri, gami da nanomaterial na “mashahuri” ɗaya da na biyu ko ma na uku na nanomaterial.Misali, kayan da aka yi wa ado da nanoparticles, core-shell (CS) da multilayer heteronanostructured kayan ana amfani da su a cikin nau'in firikwensin nau'in II kuma za a tattauna dalla-dalla a ƙasa.
Don kayan aikin heteronanostructure na farko (an yi ado heteronanostructure), kamar yadda aka nuna a cikin siffa 2b (1), ana haɗa tashoshi masu gudanarwa na firikwensin ta hanyar kayan tushe.Saboda samuwar heterojunctions, gyare-gyaren nanoparticles na iya samar da ƙarin wuraren amsawa don tallan iskar gas ko ɓarna, kuma yana iya aiki azaman mai kara kuzari don haɓaka aikin ji109,122,123,124.Yuan et al.41 ya lura cewa yin ado na WO3 nanowires tare da CeO2 nanodots na iya samar da ƙarin wuraren tallatawa a CeO2@WO3 heterointerface da CeO2 surface da kuma samar da karin chemisorbed oxygen jinsunan domin dauki tare da acetone.Gunawan et al.125. An ƙaddamar da firikwensin acetone mai matsananciyar hankali dangane da nau'i-nau'i guda ɗaya Au@α-Fe2O3 kuma an lura cewa ana sarrafa ma'aunin firikwensin ta hanyar kunna ƙwayoyin O2 a matsayin tushen oxygen.Kasancewar Au NPs na iya aiki azaman mai haɓakawa da ke haɓaka rarrabuwar ƙwayoyin iskar oxygen zuwa iskar oxygen ta lattice don iskar oxygenation na acetone.An samu irin wannan sakamakon ta Choi et al.9 inda aka yi amfani da mai kara kuzari na Pt don raba kwayoyin oxygen da aka haɗa su cikin nau'in oxygen mai ionized da haɓaka amsa mai mahimmanci ga acetone.A cikin 2017, wannan ƙungiyar bincike ta nuna cewa bimetallic nanoparticles sun fi dacewa a cikin catalysis fiye da nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i) wanda ke amfani da kwayoyin apoferritin. matsakaicin girman kasa da 3 nm.Sa'an nan, ta yin amfani da hanyar electrospinning, PtM @ WO3 nanofibers an samu don ƙara yawan hankali da zaɓaɓɓu zuwa acetone ko H2S (Fig. 5b-g).Kwanan nan, masu haɓaka zarra guda ɗaya (SACs) sun nuna kyakkyawan aiki mai ƙarfi a fagen catalysis da bincike na iskar gas saboda matsakaicin ingancin amfani da zarra da tsarin lantarki da aka gyara127,128.Shin et al.129 sun yi amfani da Pt-SA anchored carbon nitride (MCN), SnCl2 da PVP nanosheets azaman tushen sinadarai don shirya Pt@MCN@SnO2 filayen layi na layi don gano gas.Duk da ƙarancin abun ciki na Pt@MCN (daga 0.13 wt.% zuwa 0.68 wt.%), aikin gano gaseous formaldehyde Pt@MCN@SnO2 ya fi sauran samfuran tunani (tsarki SnO2, MCN @ SnO2 da Pt NPs @ SnO2 )..Ana iya dangana wannan kyakkyawan aikin ganowa zuwa matsakaicin ingancin atomic na Pt SA mai kara kuzari da mafi ƙarancin ɗaukar hoto na wuraren aiki na SnO2129.
Hanyar da aka ɗora Apoferritin don samun PtM-apo (PtPd, PtRh, PtNi) nanoparticles;kaddarorin gas mai ƙarfi na bd pristine WO3, PtPd@WO3, PtRn@WO3, da Pt-NiO@WO3 nanofibers;bisa, alal misali, akan kaddarorin zaɓi na PtPd@WO3, PtRn@WO3 da Pt-NiO@WO3 nanofiber firikwensin zuwa 1 ppm na iskar gas 126
Bugu da kari, heterojunctions kafa tsakanin scaffold kayan da nanoparticles kuma iya yadda ya kamata daidaita tafiyar tashoshi ta hanyar radial modulation inji don inganta firikwensin yi130,131,132.A kan fig.Hoto 6a yana nuna halayen firikwensin SnO2 mai tsabta da Cr2O3@SnO2 nanowires don ragewa da iskar gas da kuma hanyoyin firikwensin daidai131.Idan aka kwatanta da tsarkakakken SnO2 nanowires, amsawar Cr2O3@SnO2 nanowires don rage iskar gas yana haɓaka sosai, yayin da martani ga iskar iskar oxygen ta ƙara tsananta.Waɗannan abubuwan mamaki suna da alaƙa da haɓakar gida na tashoshin gudanarwa na SnO2 nanowires a cikin radial shugabanci na kafa pn heterojunction.Ana iya kunna juriyar firikwensin ta hanyar canza faɗin EDL akan saman tsantsar SnO2 nanowires bayan fallasa ga ragewa da iskar gas.Duk da haka, don Cr2O3 @ SnO2 nanowires, DEL na farko na SnO2 nanowires a cikin iska yana karuwa idan aka kwatanta da nanowires na SnO2 mai tsabta, kuma an dakatar da tashar gudanarwa saboda samuwar heterojunction.Sabili da haka, lokacin da firikwensin ya fallasa ga raguwar iskar gas, ana fitar da electrons ɗin da aka kama a cikin nanowires na SnO2 kuma EDL ya ragu sosai, yana haifar da mafi girman hankali fiye da nanowires na SnO2.Sabanin haka, lokacin canzawa zuwa iskar iskar oxygen, fadada DEL yana iyakance, yana haifar da ƙarancin hankali.An lura da irin wannan sakamako na mayar da martani ta hanyar Choi et al., 133 wanda SnO2 nanowires da aka yi wa ado tare da p-type WO3 nanoparticles ya nuna mahimmancin ingantaccen martani mai mahimmanci don rage gas, yayin da na'urori masu adon SnO2 da aka yi wa ado sun inganta haɓakar haɓakar iskar gas.TiO2 nanoparticles (Fig. 6b) 133. Wannan sakamakon ya fi dacewa saboda ayyuka daban-daban na SnO2 da MOS (TiO2 ko WO3) nanoparticles.A cikin nau'in p-type (n-type) nanoparticles, tashar gudanarwa na kayan aikin (SnO2) yana faɗaɗa (ko kwangila) a cikin jagorancin radial, sa'an nan kuma, a ƙarƙashin aikin raguwa (ko hadawan abu da iskar shaka), ƙarin haɓaka (ko ragewa) na tashar gudanarwa na SnO2 - rib) na gas (Fig. 6b).
Tsarin gyare-gyare na radial wanda LF MOS da aka gyara.Takaitaccen martanin iskar gas zuwa 10 ppm ragewa da iskar gas dangane da tsantsar SnO2 da Cr2O3@SnO2 nanowires da madaidaitan tsarin ƙirar tsari;da tsare-tsare masu dacewa na WO3@SnO2 nanorods da tsarin ganowa133
A cikin bilayer da multilayer heterostructure na'urorin, tashar gudanarwa na na'urar ta mamaye Layer (yawanci Layer na kasa) a cikin hulɗar kai tsaye tare da na'urorin lantarki, kuma heterojunction da aka kafa a mahaɗin nau'i biyu na iya sarrafa motsi na kasa Layer. .Sabili da haka, lokacin da iskar gas ke hulɗa tare da saman Layer, za su iya tasiri sosai akan tashoshin gudanarwa na Layer na ƙasa da juriya 134 na na'urar.Misali, Kumar et al.77 ya ruwaito sabanin hali na TiO2@NiO da NiO@TiO2 yadudduka biyu don NH3.Wannan bambance-bambancen ya samo asali ne saboda tashoshi masu sarrafa na'urori masu auna firikwensin guda biyu sun mamaye yadudduka na kayan daban-daban (NiO da TiO2, bi da bi), sannan kuma bambance-bambancen tashoshi masu sarrafawa sun bambanta77.
Bilayer ko multilayer heteronanostructures yawanci ana samarwa ta hanyar sputtering, atomic Layer deposition (ALD) da centrifugation56,70,134,135,136.Kaurin fim ɗin da yankin lamba na kayan biyu za a iya sarrafawa da kyau.Figures 7a da b suna nuna NiO @ SnO2 da Ga2O3 @ WO3 nanofilms da aka samu ta hanyar sputtering don gano ethanol135,137.Duk da haka, waɗannan hanyoyin gabaɗaya suna samar da fina-finai masu lebur, kuma waɗannan fina-finai masu lebur ba su da hankali fiye da nanostructured na 3D saboda ƙayyadaddun yanki na musamman da iskar gas.Sabili da haka, an kuma ba da shawarar dabarun samar da ruwa-lokaci don ƙirƙira fina-finai na bilayer tare da matsayi daban-daban don haɓaka aikin fahimta ta hanyar haɓaka takamaiman yanki41,52,138.Zhu et al139 sun haɗu da sputtering da fasahar hydrothermal don samar da ZnO nanowires da aka ba da umarni sosai akan SnO2 nanowires (ZnO @ SnO2 nanowires) don gano H2S (Fig. 7c).Amsar sa ga 1 ppm H2S sau 1.6 ya fi na firikwensin firikwensin da aka watsar ZnO@SnO2 nanofilms.Liu et al.52 ya ba da rahoton babban firikwensin H2S yana amfani da matakai biyu a cikin hanyar saka sinadarai don ƙirƙira tsarin SnO2@NiO nanostructures wanda ke biye da haɓakar thermal (Fig. 10d).Idan aka kwatanta da na al'ada sputtered SnO2@NiO fina-finan bilayer, da azanci aiki na SnO2@NiO tsarin bilayer yana da matukar inganta saboda karuwa a cikin takamaiman yanki52,137.
Na'urar firikwensin gas sau biyu bisa MOS.NiO @ SnO2 nanofilm don gano ethanol;137b Ga2O3 @ WO3 nanofilm don gano ethanol;135c sosai oda SnO2@ZnO tsarin matsayi na bilayer don gano H2S;139d SnO2@NiO tsarin tsarin bilayer don gano H2S52.
A cikin nau'in na'urori na II bisa tushen heteronanostructures (CSHNs), tsarin ji na jiki ya fi rikitarwa, tun da tashoshin gudanarwa ba su iyakance ga harsashi na ciki ba.Duk hanyar masana'anta da kauri (hs) na fakitin na iya ƙayyade wurin tashoshin gudanarwa.Misali, lokacin amfani da hanyoyin haɗin ƙasa zuwa sama, tashoshi masu sarrafawa yawanci suna iyakance ne zuwa ainihin ciki, wanda yayi kama da tsari zuwa sifofin na'urori biyu ko multilayer (Fig. 2b (3)) 123, 140, 141, 142, 143. Xu da al.144 ya ba da rahoton wata hanya ta ƙasa don samun CSHN NiO @ α-Fe2O3 da CuO@α-Fe2O3 ta hanyar saka wani Layer na NiO ko CuO NPs akan α-Fe2O3 nanorods wanda tashar gudanarwa ta iyakance ta tsakiya.(nanorods α-Fe2O3).Liu et al.142 kuma ya yi nasarar taƙaita tashar gudanarwa zuwa babban ɓangaren CSHN TiO2 @ Si ta hanyar saka TiO2 akan shirye-shiryen silicon nanowires.Don haka, halayen sa (nau'in p-type ko n-type) ya dogara ne kawai akan nau'in semiconductor na silicon nanowire.
Duk da haka, yawancin na'urori masu auna firikwensin CSHN (Fig. 2b (4)) an ƙirƙira su ta hanyar canja wurin foda na kayan CS da aka haɗa akan kwakwalwan kwamfuta.A wannan yanayin, hanyar gudanarwa na firikwensin yana shafar kauri na gidaje (hs).Kungiyar Kim sun binciki tasirin hs akan aikin gano iskar gas kuma sun ba da shawarar yiwuwar ganowa100,112,145,146,147,148. An yi imani da cewa abubuwa biyu suna taimakawa wajen fahimtar tsarin wannan tsari: (1) radial modulation na EDL na harsashi da (2) tasirin tasirin filin lantarki (Fig. 8) 145. Masu binciken sun ambaci cewa tashar gudanarwa. na masu ɗaukar kaya galibi ana keɓance su ne a saman harsashi lokacin hs> λD na harsashi145. An yi imani da cewa abubuwa biyu suna taimakawa wajen fahimtar tsarin wannan tsari: (1) radial modulation na EDL na harsashi da (2) tasirin tasirin filin lantarki (Fig. 8) 145. Masu binciken sun ambaci cewa tashar gudanarwa. na masu ɗaukar kaya galibi ana keɓance su ne a saman harsashi lokacin hs> λD na harsashi145. Считается, что в механизме восприятия этой структуры участвуют два фактора: (1) радиальная модуляция ДЭС оболочки и (2) эффект размытия электрического поля (рис. 8) 145. Исследователи отметили, что канал проводимости носителей в основном приурочено к оболочке, когда hs > λD оболочки145. An yi imani da cewa abubuwa biyu suna cikin tsarin fahimtar wannan tsari: (1) radial modulation na EDL na harsashi da (2) tasirin blurring filin lantarki (Fig. 8) 145. Masu binciken sun lura cewa. tashar jigilar jigilar jigilar kayayyaki an keɓe ta ne a cikin harsashi lokacin hs> λD shells145.An yi imani da cewa abubuwa biyu suna taimakawa wajen gano hanyar gano wannan tsari: (1) radial modulation na DEL na harsashi da (2) tasirin filin lantarki (Fig. 8) 145.研究人员提到传导通道当壳层的hs > λD145 时，载流子的数量主要局限于壳层。 > λD145 时，载流子的数量主要局限于壳层。 Исследователи отметили, что канал проводимости Когда hs > λD145 оболочки, количество носителей в. Masu binciken sun lura cewa tashar gudanarwa Lokacin hs> λD145 na harsashi, adadin masu ɗaukar kaya yana iyakance ta harsashi.Sabili da haka, a cikin juzu'in juriya na firikwensin dangane da CSHN, radial modulation na cladding DEL ya yi nasara (Fig. 8a).Duk da haka, a hs ≤ λD na harsashi, ƙwayoyin iskar oxygen da aka yi wa harsashi da kuma heterojunction da aka kafa a CS heterojunction sun ƙare gaba daya na electrons. Sabili da haka, tashar gudanarwa ba wai kawai tana cikin cikin harsashi ba amma har ma a wani bangare a cikin sashin mahimmanci, musamman lokacin hs <λD na harsashi Layer. Sabili da haka, tashar gudanarwa ba wai kawai tana cikin cikin harsashi ba amma har ma a wani bangare a cikin sashin mahimmanci, musamman lokacin hs <λD na harsashi Layer. Поэтому канал проводимости располагается Sabili da haka, tashar gudanarwa tana samuwa ba kawai a cikin harsashi ba, amma har ma a cikin ɓangaren mahimmanci, musamman a hs <λD na harsashi Layer.因此，传导通道不仅位于壳层内部，而且部分位于芯部，尤其是当壳层的hs < λD . hs <λD 时. Поэтому канал проводимости располагается не только внутри оболочky, но и частично в сердцевине, особир. Saboda haka, tashar gudanarwa ba wai kawai a cikin harsashi ba, amma har ma a wani ɓangare a cikin ainihin, musamman a hs <λD na harsashi.A wannan yanayin, duka harsashi na lantarki da aka ƙare da kuma ɓangaren ɓangaren da ya ƙare suna taimakawa wajen daidaita juriya na dukan CSHN, yana haifar da tasirin wutsiya na lantarki (Fig. 8b).Wasu nazarin sun yi amfani da ra'ayi na juzu'i na EDL maimakon wutsiya ta wutar lantarki don nazarin tasirin hs100,148.Yin la'akari da waɗannan gudunmawar guda biyu, jimlar juriya na CSHN ya kai darajarta mafi girma lokacin da hs yayi daidai da sheath λD, kamar yadda aka nuna a cikin siffa 8c.Saboda haka, mafi kyawun hs na CSHN na iya zama kusa da harsashi λD, wanda ya yi daidai da gwaje-gwajen gwaji99,144,145,146,149.Yawancin karatu sun nuna cewa hs kuma na iya rinjayar ji na CSHN na tushen pn-heterojunction firikwensin40,148.Li et al.148 da Bai et al.40 a tsari ya bincika tasirin hs akan aikin pn-heterojunction CSHN firikwensin, kamar TiO2@CuO da ZnO@NiO, ta hanyar canza zagayowar ALD mai rufewa.Sakamakon haka, halayen azanci sun canza daga nau'in p-type zuwa nau'in n tare da haɓaka hs40,148.Wannan hali ya faru ne saboda gaskiyar cewa a farkon (tare da iyakacin adadin hawan ALD) ana iya ɗaukar tsarin heterostructures azaman gyare-gyaren heteronostructures.Don haka, tashar gudanarwa tana iyakance ta ainihin Layer (p-type MOSFET), kuma firikwensin yana nuna halin gano nau'in p.Yayin da adadin zagayowar ALD ke ƙaruwa, cladding Layer (n-type MOSFET) ya zama mai ci gaba kuma yana aiki azaman tashar gudanarwa, yana haifar da hankali na nau'in n.An ba da rahoton irin wannan halin canjin azanci don pn reshen heteronanostructures 150,151.Zhou et al.150 sun bincika hankalin Zn2SnO4@Mn3O4 reshen heteronostructures ta hanyar sarrafa abun ciki na Zn2SnO4 akan saman Mn3O4 nanowires.Lokacin da Zn2SnO4 nuclei ya samo asali akan saman Mn3O4, an lura da yanayin p-type.Tare da ƙarin haɓakawa a cikin abun ciki na Zn2SnO4, firikwensin dangane da reshe Zn2SnO4@Mn3O4 heteronanostructures yana canzawa zuwa halayen firikwensin nau'in n.
An nuna bayanin ra'ayi na tsarin firikwensin aiki biyu na CS nanowires.wani juriya na juriya saboda radial modulation of electron-depleted shells, b Mummunan sakamako na smearing akan juriya juriya, da kuma jimlar juriya na CS nanowires saboda haɗuwa da tasirin biyu 40
A ƙarshe, nau'in na'urori masu auna firikwensin II sun haɗa da nanostructures daban-daban na matsayi daban-daban, kuma aikin firikwensin ya dogara sosai kan tsarin tashoshi masu gudanarwa.Sabili da haka, yana da mahimmanci don sarrafa matsayi na tashar gudanarwa na firikwensin kuma amfani da samfurin MOS mai dacewa da heteronostructured don nazarin tsawaita tsarin ji na nau'in firikwensin II.
Nau'in na'urar firikwensin nau'in nau'in firikwensin ba kowa ba ne, kuma tashar gudanarwar ta dogara ne akan wani heterojunction da aka samar tsakanin semiconductor guda biyu da aka haɗa da na'urori biyu, bi da bi.Tsarin na'ura na musamman yawanci ana samun su ta hanyar fasahar micromachining kuma hanyoyin gano su sun sha bamban da na'urorin firikwensin guda biyu da suka gabata.Hanya na IV na na'urar firikwensin Nau'in III yawanci yana nuna halaye na gyare-gyare na yau da kullun saboda haɓakar yanayin yanayin 48,152,153.Za'a iya siffanta siffar siffa ta I-V ta kyakkyawan yanayin heterojunction ta hanyar thermionic na'urar fitarwar lantarki akan tsayin shingen heterojunction152,154,155.
inda Va shine wutar lantarki na son rai, A shine yanki na na'ura, k shine Boltzmann akai-akai, T shine cikakken zafin jiki, q shine cajin mai ɗaukar nauyi, Jn da Jp sune ramuka da ƙarancin wutar lantarki na yanzu, bi da bi.IS tana wakiltar juriyar jikewar halin yanzu, wanda aka ayyana da: 152,154,155
Sabili da haka, jimlar halin yanzu na pn heterojunction ya dogara ne akan canji a cikin tattarawar masu ɗaukar kaya da kuma canjin tsayin shinge na heterojunction, kamar yadda aka nuna a cikin daidaito (3) da (4) 156
inda nn0 da pp0 sune ma'auni na electrons (ramuka) a cikin nau'in n-type (p-type) MOS, \ (V_{bi} ^ 0 \) shine ginannen yuwuwar, Dp (Dn) shine ma'aunin rarrabawa na electrons (ramuka), Ln (Lp) shine tsayin yaduwa na electrons (ramuka), ΔEv (ΔEc) shine motsin makamashi na valence band (conduction band) a heterojunction.Ko da yake yawan adadin na yanzu ya yi daidai da girman mai ɗaukar kaya, yana da ƙaƙƙarfan ƙetare daidai da \(V_{bi}^0\).Sabili da haka, gabaɗayan canji a cikin yawa na yanzu yana da ƙarfi ya dogara da daidaitawar tsayin shingen heterojunction.
Kamar yadda aka ambata a sama, ƙirƙirar MOSFETs na hetero-nanostructured (misali, nau'in I da nau'in na'urori na II) na iya haɓaka aikin firikwensin sosai, maimakon ɗayan abubuwan haɗin gwiwa.Kuma don nau'in na'urori na III, amsawar heteronostructure na iya zama sama da abubuwa biyu48,153 ko sama da ɗayan ɗayan76, dangane da sinadarai na kayan.Rahotanni da yawa sun nuna cewa amsawar heteronostructures ya fi girma fiye da na kashi ɗaya lokacin da ɗaya daga cikin abubuwan da ke da alaƙa ba shi da hankali ga iskar gas48,75,76,153.A wannan yanayin, iskar gas ɗin da aka yi niyya zai yi hulɗa tare da Layer mai mahimmanci kuma ya haifar da motsi Ef na Layer mai mahimmanci da canji a tsayin shingen heterojunction.Sa'an nan jimlar halin yanzu na na'urar za ta canza sosai, tun da yake yana da alaƙa da tsayin shingen heterojunction bisa ga lissafin.(3) da (4) 48,76,153.Koyaya, lokacin da nau'in n-type da nau'in p-type ke kula da iskar gas ɗin da aka yi niyya, aikin ganowa na iya zama wani wuri tsakanin.José et al.76 ya samar da firikwensin NiO/SnO2 mai banƙyama na NO2 firikwensin ta hanyar sputtering kuma ya gano cewa firikwensin firikwensin ya fi girma ne kawai daga na firikwensin tushen NiO, amma ƙasa da na tushen firikwensin SnO2.firikwensinWannan lamarin ya faru ne saboda gaskiyar cewa SnO2 da NiO suna nuna sabanin halayen zuwa NO276.Har ila yau, saboda abubuwan biyu suna da nau'ikan iskar gas daban-daban, suna iya samun hali iri ɗaya don gano oxidizing da rage iskar gas.Misali, Kwon et al.157 ya ba da shawarar NiO/SnO2 pn-heterojunction gas firikwensin ta hanyar tsiyayar da ba ta dace ba, kamar yadda aka nuna a hoto. 9a.Abin sha'awa shine, NiO/SnO2 pn-heterojunction firikwensin ya nuna irin yanayin ji na H2 da NO2 (Fig. 9a).Don warware wannan sakamakon, Kwon et al.157 ya bincikar da tsari yadda NO2 da H2 ke canza ma'auni mai ɗaukar hoto da kuma kunna \(V_{bi}^0 \) na duka kayan ta amfani da halayen IV da simintin kwamfuta (Fig. 9bd).Figures 9b da c suna nuna ikon H2 da NO2 don canza yawan masu ɗauka na firikwensin bisa p-NiO (pp0) da n-SnO2 (nn0), bi da bi.Sun nuna cewa pp0 na nau'in p-type NiO ya canza kadan a cikin yanayin NO2, yayin da ya canza sosai a cikin yanayin H2 (Fig. 9b).Duk da haka, don nau'in SnO2, nn0 yana nuna halin da akasin haka (Fig. 9c).Dangane da waɗannan sakamakon, marubutan sun kammala cewa lokacin da aka yi amfani da H2 zuwa firikwensin dangane da NiO/SnO2 pn heterojunction, karuwa a nn0 ya haifar da karuwa a Jn, kuma \ (V_{bi} ^ 0 \) ya haifar da raguwa a cikin amsa (Fig. 9d).Bayan bayyanarwa zuwa NO2, duka babban raguwa a nn0 a cikin SnO2 da ƙananan karuwa a cikin pp0 a cikin NiO yana haifar da raguwa mai yawa a \ (V_{bi} ^ 0 \), wanda ke tabbatar da karuwa a cikin amsawar hankali (Fig. 9d). ) 157 A ƙarshe, canje-canje a cikin tattarawar masu ɗaukar kaya da \ (V_{bi} ^ 0 \) yana haifar da canje-canje a cikin jimlar halin yanzu, wanda ya kara rinjayar ikon ganowa.
Tsarin ji na firikwensin gas ya dogara ne akan tsarin na'urar Nau'in III.Hotunan ƙetare-tsalle na lantarki (SEM), p-NiO / n-SnO2 nanocoil na'urar da kayan firikwensin p-NiO / n-SnO2 nanocoil heterojunction firikwensin a 200 ° C don H2 da NO2;b, SEM-section na c-na'urar, da sakamakon kwaikwayo na na'urar tare da p-NiO b-Layer da n-SnO2 c-Layer.Na'urar firikwensin b p-NiO da ma'aunin firikwensin c n-SnO2 kuma sun dace da halayen I-V a cikin busasshiyar iska da bayan bayyanar H2 da NO2.Taswirar nau'i biyu na girman b-rami a cikin p-NiO da taswirar c-electrons a cikin Layer n-SnO2 tare da sikelin launi an tsara su ta amfani da software na Sentaurus TCAD.d Sakamakon kwaikwaiyo yana nuna taswirar 3D na p-NiO/n-SnO2 a busasshiyar iska, H2 da NO2157 a cikin muhalli.
Baya ga sinadarai na kayan da kanta, tsarin na'urar Nau'in III ya nuna yiwuwar samar da na'urori masu amfani da iskar gas, wanda ba zai yiwu ba tare da na'urorin Nau'in I da Nau'in II.Saboda filin lantarki na asali (BEF), pn heterojunction diode Tsarin ana amfani da su don gina na'urorin photovoltaic da kuma nuna yuwuwar yin na'urorin gas na photoelectric mai sarrafa kansu a zazzabi na ɗaki ƙarƙashin haske74,158,159,160,161.BEF a heterointerface, wanda ya haifar da bambanci a cikin matakan Fermi na kayan, kuma yana ba da gudummawa ga rabuwa na nau'i-nau'i na electron-rami.Amfanin na'urar firikwensin iskar gas na photovoltaic mai sarrafa kansa shine ƙarancin wutar lantarki kamar yadda zai iya ɗaukar makamashin hasken haske sannan kuma sarrafa kanta ko wasu ƙananan na'urori ba tare da buƙatar tushen wutar lantarki na waje ba.Misali, Tanuma da Sugiyama162 sun ƙirƙira NiO/ZnO pn heterojunctions azaman ƙwayoyin rana don kunna na'urori masu auna firikwensin polycrystalline CO2 na tushen SnO2.Gad et al.74 ya ba da rahoton firikwensin iskar gas mai sarrafa kansa wanda ya dogara da Si / ZnO @ CdS pn heterojunction, kamar yadda aka nuna a cikin siffa 10a.Madaidaitan ZnO nanowires an girma kai tsaye akan nau'in siliki na p-nau'in don samar da Si/ZnO pn heterojunctions.Sa'an nan CdS nanoparticles an gyaggyara a saman ZnO nanowires ta hanyar gyare-gyaren sinadarai.A kan fig.10a yana nuna layin Si/ZnO@CdS sakamakon amsawar firikwensin O2 da ethanol.Ƙarƙashin haske, wutar lantarki mai buɗewa (Voc) saboda rabuwar nau'i-nau'i-nau'i-nau'i na lantarki a lokacin BEP a Si/ZnO heterointerface yana ƙaruwa tare da adadin diodes da aka haɗa74,161.Voc za a iya wakilta ta hanyar ma'auni.(5) 156,
inda ND, NA, da Ni sune tarin masu ba da gudummawa, masu karɓa, da masu ɗaukar kaya, bi da bi, da k, T, da q sun kasance ma'auni ɗaya kamar a cikin lissafin baya.Lokacin da aka fallasa su zuwa iskar oxygen, suna fitar da electrons daga ZnO nanowires, wanda ke haifar da raguwar \ (N_D ^ {ZnO} \) da Voc.Sabanin haka, raguwar gas ya haifar da karuwa a cikin Voc (Fig. 10a).Lokacin yin ado da ZnO tare da nanoparticles na CdS, electrons masu ɗorewa a cikin CdS nanoparticles ana allura a cikin rukunin gudanarwa na ZnO kuma suna yin hulɗa tare da iskar gas ɗin da aka tallata, don haka ƙara haɓakar fahimta74,160.Hoffmann et al.160, 161 (Hoto 10b).Ana iya shirya wannan firikwensin ta amfani da layin amine-aikin ZnO nanoparticles ([3- (2-aminoethylamino) propyl] trimethoxysilane) (amino-functionalized-SAM) da thiol ((3-mercaptopropyl) -aikin, don daidaita aikin aikin. na iskar gas don gano zaɓi na NO2 (trimethoxysilane) (thiol-functionalized-SAM)) (Fig. 10b) 74,161.
Na'urar firikwensin iskar gas mai ɗaukar hoto mai sarrafa kansa bisa tsarin na'urar nau'in III.na'urar firikwensin photovoltaic gas mai sarrafa kansa dangane da Si / ZnO @ CdS, na'ura mai sarrafa kansa da kuma amsawar firikwensin ga oxidized (O2) da rage (1000 ppm ethanol) gas a ƙarƙashin hasken rana;74b Na'urar firikwensin iskar gas mai sarrafa kansa dangane da Si ZnO/ZnO na'urori masu auna firikwensin da martanin firikwensin ga iskar gas daban-daban bayan aikin ZnO SAM tare da amines da thiols 161
Sabili da haka, lokacin da ake magana game da mahimmancin mahimmanci na nau'in na'urori na III, yana da mahimmanci don ƙayyade canji a cikin tsayin shingen heterojunction da kuma ikon gas don rinjayar maida hankali mai ɗauka.Bugu da ƙari, hasken wuta zai iya haifar da masu ɗaukar hoto waɗanda ke amsawa da iskar gas, wanda ke da alƙawarin gano iskar gas mai sarrafa kansa.
Kamar yadda aka tattauna a cikin wannan bita na wallafe-wallafen, an ƙirƙira nau'ikan tsarin MOS daban-daban don inganta aikin firikwensin.An nemo bayanan yanar gizo na Kimiyya don mahimman kalmomi daban-daban (kamfanin ƙarfe oxide, core-sheath metal oxides, layered metal oxides, and gas analyzers) da kuma halaye na musamman (yawanci, azanci / zaɓi, yuwuwar samar da wutar lantarki, masana'antu) .Hanyar Ana nuna halayen uku daga cikin waɗannan na'urori uku a cikin Tebur na 2. Gabaɗayan ra'ayi na ƙira don manyan firikwensin iskar gas ana tattauna su ta hanyar nazarin mahimman abubuwa uku da Yamazoe ya gabatar.Hanyoyi don firikwensin Heterostructure na MOS Don fahimtar abubuwan da ke tasiri na'urori masu auna iskar gas, sigogin MOS daban-daban (misali, girman hatsi, zafin aiki, lahani da ƙarancin iskar oxygen, buɗaɗɗen jiragen sama) an yi nazari sosai.Tsarin na'ura, wanda kuma yana da mahimmanci ga halayyar firikwensin firikwensin, an yi watsi da shi kuma ba kasafai ake tattaunawa ba.Wannan bita ta tattauna hanyoyin da ake bi don gano nau'ikan tsarin na'ura guda uku.
Tsarin girman hatsi, hanyar masana'anta, da adadin heterojunctions na kayan ji a cikin firikwensin Nau'in I na iya tasiri sosai ga ji na firikwensin.Bugu da ƙari, halayen firikwensin kuma yana shafar rabon molar na sassan.Nau'in nau'in na'ura na II (nau'in kayan ado na heteronostructures, bilayer ko multilayer fina-finai, HSSNs) sune mafi mashahuri tsarin na'ura wanda ya ƙunshi abubuwa biyu ko fiye, kuma kashi ɗaya ne kawai aka haɗa da lantarki.Don wannan tsarin na'urar, ƙayyade wurin tashoshin gudanarwa da sauye-sauyen dangi yana da mahimmanci wajen nazarin tsarin fahimta.Saboda nau'ikan na'urori na II sun haɗa da tsarin tsarin heterononostructure daban-daban, an gabatar da hanyoyin ganowa daban-daban.A cikin nau'in nau'i na nau'i na nau'i na III, tashar gudanarwa ta mamaye wani heterojunction da aka kafa a heterojunction, kuma tsarin tsinkaye ya bambanta.Sabili da haka, yana da mahimmanci don ƙayyade canjin tsayin shingen heterojunction bayan bayyanar iskar gas ɗin da aka yi niyya zuwa firikwensin nau'in III.Tare da wannan zane, ana iya yin na'urori masu amfani da iskar gas na photovoltaic don rage yawan wutar lantarki.Duk da haka, tun da tsarin ƙirƙira na yanzu yana da wuyar gaske kuma hankali ya fi ƙasa da na'urorin gas na MOS na gargajiya na chemo-resistive gas, har yanzu ana samun ci gaba mai yawa a cikin binciken na'urori masu amfani da iskar gas.
Babban abũbuwan amfãni na gas MOS na'urori masu auna firikwensin tare da heteronostructures heteronostructures ne da sauri da kuma mafi girma hankali.Koyaya, wasu mahimman matsalolin na'urori masu auna iskar gas na MOS (misali, babban zafin jiki na aiki, kwanciyar hankali na dogon lokaci, zaɓi mara kyau da haɓakawa, tasirin zafi, da sauransu) har yanzu suna wanzu kuma suna buƙatar magance su kafin a iya amfani da su a aikace-aikace masu amfani.Na'urori masu auna iskar gas na MOS na zamani yawanci suna aiki a yanayin zafi mai yawa kuma suna cinye ƙarfi da yawa, wanda ke shafar kwanciyar hankali na dogon lokaci na firikwensin.Akwai hanyoyin gama gari guda biyu don magance wannan matsala: (1) haɓaka na'urorin firikwensin ƙananan wuta;(2) haɓaka sabbin abubuwa masu mahimmanci waɗanda zasu iya aiki a ƙananan zafin jiki ko ma a cikin zafin jiki.Hanya ɗaya don haɓaka guntuwar firikwensin ƙananan ƙarfi shine rage girman firikwensin ta hanyar ƙirƙira faranti masu zafi da ke kan yumbu da silicon163.Faranti masu dumama yumbu suna cinye kusan 50-70 mV kowace firikwensin, yayin da ingantattun faranti masu dumama siliki na iya cinye ƙasa da 2mW a kowane firikwensin yayin da yake ci gaba da aiki a 300 ° C163,164.Haɓaka sababbin kayan ji shine hanya mai mahimmanci don rage yawan wutar lantarki ta hanyar rage yawan zafin jiki, kuma yana iya inganta kwanciyar hankali na firikwensin.Yayin da girman MOS ya ci gaba da ragewa don ƙara yawan hankali na firikwensin, kwanciyar hankali na thermal na MOS ya zama kalubale, wanda zai iya haifar da raguwa a cikin siginar firikwensin165.Bugu da ƙari, babban zafin jiki yana inganta yaduwar kayan aiki a heterointerface da kuma samar da nau'i-nau'i masu gauraye, wanda ke rinjayar kayan lantarki na firikwensin.Masu binciken sun ba da rahoton cewa za a iya rage madaidaicin zafin jiki na firikwensin ta hanyar zaɓar kayan ji masu dacewa da haɓaka tsarin MOS heteronanostructures.Neman hanyar ƙananan zafin jiki don ƙirƙira ingantacciyar ƙirar MOS heteronanostructures shine wata hanya mai ban sha'awa don inganta kwanciyar hankali.
Zaɓin na'urori masu auna firikwensin MOS wani lamari ne mai amfani kamar yadda iskar gas daban-daban ke kasancewa tare da iskar gas, yayin da na'urori masu auna firikwensin MOS galibi suna kula da iskar gas fiye da ɗaya kuma galibi suna nuna ƙwarewar giciye.Don haka, haɓaka zaɓin firikwensin zuwa iskar gas ɗin da ake nufi da sauran iskar gas yana da mahimmanci ga aikace-aikacen aiki.A cikin ƴan shekarun da suka gabata, an magance zaɓin ta hanyar gina tsararrun na'urori masu auna iskar gas da ake kira "electronic noses (E-nose)" a haɗe tare da ƙididdigar ƙididdigar lissafi kamar su horar da ƙididdige ƙididdigewa (LVQ), babban bincike na bangaren (PCA), da sauransu e.Matsalolin jima'i.M000 city murabba'i (pls) 31, 32, 32, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34,39 don gane gas169.Koyaya, haɓaka adadin na'urori masu auna firikwensin yawanci yana buƙatar matakai masu rikitarwa masu rikitarwa, don haka yana da mahimmanci a sami hanya mai sauƙi don haɓaka aikin hancin lantarki.Bugu da ƙari, gyaggyarawa MOS tare da wasu kayan kuma na iya ƙara yawan zaɓi na firikwensin.Misali, ana iya samun gano zaɓi na H2 saboda kyakkyawan aikin haɓakawa na MOS wanda aka gyara tare da NP Pd.A cikin 'yan shekarun nan, wasu masu bincike sun rufe MOS MOF surface don inganta firikwensin zabin ta hanyar girman girman171,172.Ƙaddamar da wannan aikin, aikin kayan aiki na iya ko ta yaya warware matsalar zaɓin zaɓi.Duk da haka, akwai sauran aiki da yawa da za a yi wajen zabar kayan da ya dace.
Maimaita halayen na'urori masu auna firikwensin da aka ƙera a ƙarƙashin yanayi iri ɗaya da hanyoyin shine wani muhimmin buƙatu don samarwa mai girma da aikace-aikace masu amfani.Yawanci, centrifugation da dipping hanyoyin hanyoyi ne masu ƙarancin farashi don ƙirƙira manyan firikwensin iskar gas.Duk da haka, a lokacin waɗannan matakai, abu mai mahimmanci yana kula da haɗuwa kuma dangantakar da ke tsakanin abu mai mahimmanci da substrate ya zama rauni68, 138, 168. A sakamakon haka, hankali da kwanciyar hankali na firikwensin ya lalace sosai, kuma aikin ya zama mai yiwuwa.Sauran hanyoyin ƙirƙira irin su sputtering, ALD, pulsed Laser deposition (PLD), da kuma taurin jiki (PVD) suna ba da damar samar da fina-finai na bilayer ko multilayer MOS kai tsaye akan siliki mai ƙima ko alumina substrates.Waɗannan fasahohin suna guje wa haɓaka kayan aiki masu mahimmanci, tabbatar da sake fasalin firikwensin, da kuma nuna yuwuwar samar da manyan sikelin na firikwensin bakin ciki-fim.Koyaya, hankalin waɗannan fina-finai na lebur gabaɗaya ya fi na 3D nanostructured kayan saboda ƙayyadaddun yanki na musamman da ƙarancin iskar gas41,174.Sabbin dabarun haɓaka tsarin MOS heteronanostructures a takamaiman wurare akan ƙayyadaddun ƙayyadaddun microarrays da daidai sarrafa girman, kauri, da ilimin halittar jiki na kayan mahimmanci suna da mahimmanci don ƙirƙira ƙarancin farashi na na'urori masu auna matakin wafer tare da haɓakawa da haɓakawa.Alal misali, Liu et al.174 ya ba da shawarar haɗaɗɗun dabarun sama-sama da ƙasa don ƙirƙira manyan kayan ƙirƙira ta hanyar girma a cikin situ Ni(OH) nanowalls a takamaiman wurare..Wafers don microburners.
Bugu da ƙari, yana da mahimmanci a yi la'akari da tasirin zafi akan firikwensin a aikace-aikace masu amfani.Kwayoyin ruwa na iya yin gogayya da kwayoyin oxygen don wuraren tallatawa a cikin kayan firikwensin kuma suna shafar alhakin firikwensin ga iskar gas da ake nufi.Kamar iskar oxygen, ruwa yana aiki a matsayin kwayoyin halitta ta hanyar jijiyar jiki, kuma yana iya kasancewa a cikin nau'i na hydroxyl radicals ko hydroxyl kungiyoyin a wurare daban-daban na oxygenation ta hanyar chemisorption.Bugu da ƙari, saboda babban matsayi da yanayin zafi mai sauƙi na yanayi, ingantaccen amsa na firikwensin ga iskar gas shine babbar matsala.An bullo da dabaru da dama don magance wannan matsala, kamar iskar iskar gas177, ramuwa da danshi da hanyoyin latti178, da kuma hanyoyin bushewa179,180.Duk da haka, waɗannan hanyoyin suna da tsada, masu rikitarwa, kuma suna rage hankali na firikwensin.An gabatar da dabaru da yawa marasa tsada don murkushe tasirin zafi.Misali, yin ado da SnO2 tare da nanoparticles Pd na iya haɓaka jujjuyawar iskar oxygen zuwa ƙwayoyin anionic, yayin da aikin SnO2 tare da kayan da ke da alaƙa mai girma ga ƙwayoyin ruwa, kamar NiO da CuO, hanyoyi biyu ne don hana dogaro da danshi akan ƙwayoyin ruwa..Sensors 181, 182, 183. Bugu da ƙari, ana iya rage tasirin zafi ta hanyar amfani da kayan hydrophobic don samar da saman hydrophobic36,138,184,185.Duk da haka, ci gaban na'urorin gas masu jurewa danshi har yanzu yana kan matakin farko, kuma ana buƙatar ƙarin dabaru don magance waɗannan batutuwa.
A ƙarshe, haɓakawa a cikin aikin ganowa (misali, hankali, zaɓin zaɓi, ƙarancin zafin aiki mafi ƙarancin aiki) an samu ta hanyar ƙirƙirar tsarin MOS heteronostructures, kuma an gabatar da ingantattun hanyoyin ganowa daban-daban.Lokacin nazarin tsarin ji na wani firikwensin firikwensin, dole ne a yi la'akari da tsarin geometric na na'urar.Za a buƙaci bincike kan sabbin kayan haɓakawa da bincike kan dabarun ƙirƙira na gaba don ƙara haɓaka ayyukan na'urori masu auna iskar gas da magance sauran ƙalubale a nan gaba.Don sarrafa sarrafa halayen firikwensin, ya zama dole a tsara tsarin gina alaƙa tsakanin hanyar roba na kayan firikwensin da aikin heteronostructures.Bugu da ƙari, nazarin abubuwan da ke faruwa a saman da kuma canje-canje a cikin heterointerfaces ta yin amfani da hanyoyin halayen zamani na iya taimakawa wajen bayyana hanyoyin da suka dace da kuma samar da shawarwari don ci gaba da na'urori masu auna firikwensin bisa ga kayan da aka tsara.A ƙarshe, nazarin dabarun ƙirƙira firikwensin zamani na iya ba da damar ƙirƙira ƙananan firikwensin iskar gas a matakin wafer don aikace-aikacen masana'anta.
Genzel, NN et al.Nazarin dogon lokaci na matakan nitrogen dioxide na cikin gida da alamun numfashi a cikin yara masu ciwon asma a cikin birane.unguwa.Halin lafiya.116, 1428-1432 (2008).
Lokacin aikawa: Nov-04-2022
