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An yi amfani da nakasa sosai wajen inganta aikin ƙwayoyin hasken rana na lead triiodide perovskite, amma tasirin lahani daban-daban akan kwanciyar hankali na α har yanzu ba a fayyace ba; A nan, ta amfani da ka'idar aiki mai yawa, mun gano hanyar lalacewa ta formamidine lead triiodide perovskite daga α-phase zuwa δ-phase kuma muna nazarin tasirin lahani daban-daban akan shingen makamashi na canjin lokaci. Sakamakon kwaikwayo ya annabta cewa gurɓatattun aidin suna iya haifar da lalacewa saboda suna rage shingen makamashi sosai don canjin lokaci na α-δ kuma suna da mafi ƙarancin kuzarin samarwa a saman perovskite. Gabatar da wani yanki mai yawa na lead oxalate mai narkewa a ruwa akan saman perovskite yana hana rushewar lokaci na α, yana hana ƙaura da canjin aidin. Bugu da ƙari, wannan dabarar tana rage haɗuwa mara radiation tsakanin fuskoki da yawa kuma tana ƙara ingancin ƙwayoyin rana zuwa 25.39% (an tabbatar da 24.92%). Na'urar da ba a rufe ta ba har yanzu za ta iya ci gaba da aiki da kashi 92% na asali bayan ta yi aiki a matsakaicin ƙarfi na tsawon awanni 550 a ƙarƙashin hasken iska mai nauyin 1.5 G.
Ingancin canza wutar lantarki (PCE) na ƙwayoyin hasken rana na perovskite (PSCs) ya kai matsayin rikodin da aka tabbatar da shi na 26% 1. Tun daga shekarar 2015, PSCs na zamani sun fi son formamidine triiodide perovskite (FAPbI3) a matsayin Layer mai ɗaukar haske saboda kyakkyawan kwanciyar hankali na zafi da kuma fifikon bandgip kusa da iyakar Shockley-Keisser na 2,3,4. Abin takaici, fina-finan FAPbI3 suna fuskantar canjin yanayi daga matakin α baƙi zuwa matakin rawaya mara perovskite δ a zafin jiki na ɗaki 5,6. Don hana samuwar matakin delta, an ƙirƙiri nau'ikan abubuwan haɗin perovskite masu rikitarwa daban-daban. Dabara mafi yawan gaske don shawo kan wannan matsalar ita ce haɗa FAPbI3 da haɗin methyl ammonium (MA+), cesium (Cs+) da bromide (Br-) ions 7,8,9. Duk da haka, hybrid perovskites suna fama da faɗaɗa bandgap da kuma rabuwar lokaci ta hanyar photoinduced, wanda ke kawo cikas ga aiki da kwanciyar hankali na PSCs10,11,12 da aka samu.
Binciken da aka yi kwanan nan ya nuna cewa tsantsar kristal guda ɗaya ba tare da wani magani ba yana da kyakkyawan kwanciyar hankali saboda kyawun kristal ɗinsa da ƙarancin lahani13,14. Saboda haka, rage lahani ta hanyar ƙara yawan crystallinity na babban FAPbI3 wata muhimmiyar dabara ce don cimma ingantaccen PSCs2,15. Duk da haka, yayin aiki da FAPbI3 PSC, raguwa zuwa matakin δ mai launin rawaya wanda ba a so wanda ba shi da perovskite δ har yanzu yana iya faruwa16. Tsarin yawanci yana farawa ne a saman da iyakokin hatsi waɗanda suka fi saurin kamuwa da ruwa, zafi da haske saboda kasancewar wurare masu lahani da yawa17. Saboda haka, passivation na saman/hatsi yana da mahimmanci don daidaita yanayin baƙi na FAPbI318. Dabaru da yawa na passivation na lahani, gami da gabatar da ƙananan perovskites, ƙwayoyin Lewis masu tushen acid, da gishirin ammonium halide, sun sami babban ci gaba a cikin formamidine PSCs19,20,21,22. Zuwa yanzu, kusan dukkan bincike sun mayar da hankali kan rawar da lahani daban-daban ke takawa wajen tantance halayen optoelectronic kamar sake haɗakar na'urar ɗaukar hoto, tsawon yaɗuwa da tsarin band a cikin ƙwayoyin hasken rana22,23,24. Misali, ana amfani da ka'idar aiki mai yawa (DFT) don yin hasashen kuzarin samuwar da kuma kama matakan kuzari na lahani daban-daban, wanda ake amfani da shi sosai don jagorantar ƙirar passivation mai amfani20,25,26. Yayin da adadin lahani ke raguwa, kwanciyar hankalin na'urar yawanci yana inganta. Duk da haka, a cikin formamidine PSCs, hanyoyin tasirin lahani daban-daban akan kwanciyar hankali na mataki da halayen photoelectric ya kamata ya bambanta gaba ɗaya. A gwargwadon iliminmu, fahimtar asali game da yadda lahani ke haifar da sauyin lokaci na cubic zuwa hexagonal (α-δ) da kuma rawar da passivation na saman ke takawa kan kwanciyar hankali na lokaci na α-FAPbI3 perovskite har yanzu ba a fahimce shi sosai ba.
A nan, mun bayyana hanyar lalata FAPbI3 perovskite daga baƙar fata α-phase zuwa rawaya δ-phase da tasirin lahani daban-daban akan shingen makamashi na canjin α-zuwa-δ-phase ta hanyar DFT. Ana hasashen cewa guraben I, waɗanda ake samarwa cikin sauƙi yayin ƙera fim da aikin na'urori, za su iya fara sauyin α-δ. Saboda haka, mun gabatar da wani Layer mai yawa na gubar oxalate (PbC2O4) wanda ba ya narkewa da sinadarai a saman FAPbI3 ta hanyar amsawar in situ. Surface na gubar oxalate (LOS) yana hana samuwar guraben I kuma yana hana ƙaura na ions na I lokacin da zafi, haske, da filayen lantarki suka motsa shi. Sakamakon LOS yana rage haɗuwa mara radiation tsakanin fuskoki da yawa kuma yana inganta ingancin FAPbI3 PSC zuwa 25.39% (wanda aka tabbatar zuwa 24.92%). Na'urar LOS da aka rufe ta riƙe kashi 92% na ingancinta na asali bayan ta yi aiki a matsakaicin wurin wutar lantarki (MPP) na tsawon sama da awanni 550 a wani nau'in iska mai kama da 1.5 G na radiation.
Mun fara yin lissafin ab initio don nemo hanyar rugujewar FAPbI3 perovskite zuwa sauyawa daga matakin α zuwa matakin δ. Ta hanyar cikakken tsarin sauye-sauyen mataki, an gano cewa an cimma canjin daga kusurwa mai girman uku [PbI6] octahedron a cikin matakin cubic α na FAPbI3 zuwa octahedron mai girman girma ɗaya [PbI6] a cikin matakin hexagonal δ na FAPbI3. karya 9. Pb-I yana samar da haɗin gwiwa a matakin farko (Int-1), kuma shingen makamashinsa ya kai 0.62 eV/cell, kamar yadda aka nuna a Hoto na 1a. Lokacin da aka canza octahedron a cikin alkiblar [0\(\bar{1}\)1], sarkar gajeriyar hexagon tana faɗaɗa daga 1×1 zuwa 1×3, 1×4 kuma a ƙarshe ta shiga matakin δ. Matsakaicin daidaitawar dukkan hanyar shine (011)α//(001)δ + [100]α//[100]δ. Daga cikin zane-zanen rarraba makamashi, za a iya gano cewa bayan nucleation na matakin δ na FAPbI3 a matakai masu zuwa, shingen makamashi ya yi ƙasa da na canjin matakin α, wanda ke nufin cewa za a hanzarta canjin matakin. A bayyane yake, matakin farko na sarrafa canjin matakin yana da mahimmanci idan muna son danne lalacewar matakin α.
tsarin canza yanayi daga hagu zuwa dama - baƙar fata FAPbI3 mataki (α-phase), farkon raba haɗin Pb-I (Int-1) da kuma ƙarin raba haɗin Pb-I (Int-2, Int-3 da Int-4) da kuma rawaya mataki FAPbI3 (delta phase). b Shingewar makamashi ga sauyin lokaci na α zuwa δ na FAPbI3 bisa ga lahani daban-daban na ciki. Layin mai dige-dige yana nuna shingen makamashi na lu'ulu'u mai kyau (0.62 eV). c Ƙarfin samuwar lahani na farko a saman gubar perovskite. Axis abscissa shine shingen makamashi na sauyin lokaci na α-δ, kuma axis ordinate shine kuzarin samuwar lahani. Sassan da aka yi wa inuwa launin toka, rawaya da kore sune nau'in I (ƙaramin EB-high FE), nau'in II (babban FE) da nau'in III (ƙaramin EB-low FE), bi da bi. d Ƙarfin samuwar lahani VI da LOS na FAPbI3 a cikin sarrafawa. shingen e I ga ƙaurar ion a cikin iko da LOS na FAPbI3. f – wakilcin tsari na ƙaurar ions I (ƙwayoyin lemu) da gLOS FAPbI3 (launin toka, gubar; shuɗi (orange), aidin (iodine mai motsi)) a cikin ikon gf (hagu: kallon sama; dama: sashin giciye, launin ruwan kasa); carbon; shuɗi mai haske - nitrogen; ja - oxygen; ruwan hoda mai haske - hydrogen). Ana bayar da bayanan tushe a cikin nau'in fayilolin bayanai na tushe.
Daga nan muka yi nazari kan tasirin lahani daban-daban na ma'aunin ciki (gami da PbFA, IFA, PbI, da IPb antisite occupation; ƙwayoyin Pbi da Ii na tsakiya; da kuma guraben VI, VFA, da VPb), waɗanda ake ɗauka a matsayin manyan abubuwan da ke haifar da lalacewar matakin atomic da makamashi an nuna su a cikin Hoto na 1b da Tebur na Ƙarin Bayani na 1. Abin sha'awa, ba duk lahani ke rage shingen makamashi na canjin matakin α-δ ba (Hoto na 1b). Mun yi imanin cewa lahani waɗanda ke da ƙarancin kuzarin samarwa da ƙananan shingen makamashi na canjin lokaci na α-δ ana ɗaukar su a matsayin masu illa ga kwanciyar hankali na lokaci. Kamar yadda aka ruwaito a baya, saman da ke da wadataccen gubar gabaɗaya ana ɗaukar su masu tasiri ga formamidine PSC27. Saboda haka, mun mai da hankali kan saman da aka ƙare da PbI2 (100) a ƙarƙashin yanayin da ke da wadataccen gubar. An nuna kuzarin samuwar lahani na lahani na ma'aunin ciki na saman a cikin Hoto na 1c da Tebur na Ƙarin Bayani na 1. Dangane da shingen makamashi (EB) da makamashin samuwar canjin lokaci (FE), an rarraba waɗannan lahani zuwa nau'i uku. Nau'i na I (ƙaramin EB-mai girman FE): Duk da cewa IPb, VFA da VPb suna rage shingen makamashi zuwa canjin mataki sosai, suna da ƙarfin samuwar manyan abubuwa. Saboda haka, mun yi imanin cewa waɗannan nau'ikan lahani suna da iyakataccen tasiri ga canjin mataki tunda ba kasafai ake samun su ba. Nau'i na II (babba EB): Saboda ingantaccen shingen makamashi na canjin lokaci na α-δ, lahani na PbI, IFA da PbFA ba sa lalata kwanciyar hankali na lokaci na α-FAPbI3 perovskite. Nau'i na III (ƙaramin EB-mai girman FE): lahani na VI, Ii da Pbi tare da ƙarancin kuzarin samuwar na iya haifar da lalacewar lokaci na baƙi. Musamman idan aka yi la'akari da mafi ƙarancin FE da EB VI, mun yi imanin cewa dabarar da ta fi tasiri ita ce rage guraben aiki na I.
Domin rage VI, mun ƙirƙiri wani kauri mai yawa na PbC2O4 don inganta saman FAPbI3. Idan aka kwatanta da sinadarai masu narkewar gishirin halide kamar phenylethylammonium iodide (PEAI) da n-octylammonium iodide (OAI), PbC2O4, wanda ba ya ɗauke da ions na halogen masu motsi, yana da karko a sinadarai, ba ya narkewa a cikin ruwa, kuma yana iya kashewa cikin sauƙi bayan an ƙarfafa shi. Kyakkyawan daidaita danshi a saman da filin lantarki na perovskite. Narkewar PbC2O4 a cikin ruwa shine 0.00065 g/L kawai, wanda ya fi ƙasa da na PbSO428. Mafi mahimmanci, ana iya shirya yadudduka masu yawa da iri ɗaya na LOS a hankali akan fina-finan perovskite ta amfani da halayen in situ (duba ƙasa). Mun yi kwaikwayon DFT na haɗin fuska tsakanin FAPbI3 da PbC2O4 kamar yadda aka nuna a cikin Hoto na 1 na Ƙarin. Tebur na 2 yana gabatar da kuzarin samuwar lahani bayan allurar LOS. Mun gano cewa LOS ba wai kawai yana ƙara kuzarin samuwar lahani na VI da 0.69–1.53 eV ba (Hoto na 1d), har ma yana ƙara ƙarfin kunnawa na I a saman ƙaura da saman fita (Hoto na 1e). A mataki na farko, ions na I suna ƙaura tare da saman perovskite, suna barin ions na VI a matsayin layi tare da shingen makamashi na 0.61 eV. Bayan gabatar da LOS, saboda tasirin hana sitiriyo, kuzarin kunnawa don ƙaura na ions na I yana ƙaruwa zuwa 1.28 eV. A lokacin ƙaura na ions na I suna barin saman perovskite, shingen makamashi a cikin VOC shima ya fi na samfurin sarrafawa (Hoto na 1e). An nuna zane-zanen tsarin ƙaura na I ions a cikin sarrafawa da LOS FAPbI3 a cikin Hoto na 1 f da g, bi da bi. Sakamakon kwaikwayon ya nuna cewa LOS na iya hana samuwar lahani na VI da kuma canjin I, ta haka yana hana canjin yanayin α zuwa δ.
An gwada martanin da ke tsakanin oxalic acid da FAPbI3 perovskite. Bayan haɗa maganin oxalic acid da FAPbI3, an samar da adadi mai yawa na farin datti, kamar yadda aka nuna a cikin Siffa ta 2. An gano samfurin foda a matsayin kayan PbC2O4 mai tsabta ta amfani da X-ray diffraction (XRD) (Siffa ta 3) da Fourier transform infrared spectroscopy (FTIR) (Siffa ta 4). Mun gano cewa oxalic acid yana narkewa sosai a cikin isopropyl alcohol (IPA) a zafin ɗaki tare da narkewar kusan 18 mg/mL, kamar yadda aka nuna a cikin Siffa ta 5. Wannan yana sa sarrafawa na gaba ya fi sauƙi tunda IPA, a matsayin ruwan da aka saba amfani da shi na passivation, baya lalata layin perovskite bayan ɗan gajeren lokaci29. Saboda haka, ta hanyar nutsar da fim ɗin perovskite a cikin maganin oxalic acid ko kuma shafa maganin oxalic acid a kan perovskite, ana iya samun PbC2O4 mai siriri da yawa cikin sauri a saman fim ɗin perovskite bisa ga lissafin sinadarai masu zuwa: H2C2O4 + FAPbI3 = PbC2O4 + FAI + HI. Ana iya narkar da FAI a cikin IPA kuma don haka a cire shi yayin girki. Ana iya sarrafa kauri na LOS ta hanyar lokacin amsawa da yawan abubuwan da suka riga suka faru.
An nuna hotunan na'urar daukar hoton lantarki ta hanyar amfani da na'urar daukar hoton lantarki (SEM) na fina-finan sarrafawa da na LOS perovskite a cikin Hotuna 2a,b. Sakamakon ya nuna cewa an kiyaye yanayin saman perovskite sosai, kuma an ajiye adadi mai yawa na ƙananan barbashi a saman hatsi, wanda ya kamata ya wakilci layin PbC2O4 wanda aka samar ta hanyar amsawar in-situ. Fim ɗin LOS perovskite yana da saman da ya ɗan yi laushi (Hoto na Ƙarin 6) da kuma kusurwar hulɗa da ruwa mafi girma idan aka kwatanta da fim ɗin sarrafawa (Hoto na Ƙarin 7). An yi amfani da na'urar daukar hoton lantarki mai ɗaukar hoto mai girman ƙuduri (HR-TEM) don bambanta layin saman samfurin. Idan aka kwatanta da fim ɗin sarrafawa (Hoto na 2c), wani yanki mai sirara mai kama da juna tare da kauri kusan nm 10 yana bayyane a saman LOS perovskite (Hoto na 2d). Ta amfani da na'urar duba electron mai kusurwa mai kusurwa mai kusurwa (HAADF-STEM) don bincika hulɗar tsakanin PbC2O4 da FAPbI3, ana iya ganin kasancewar yankunan crystalline na FAPbI3 da yankunan da ba su da siffar PbC2O4 a sarari (Hoto na Ƙari na 8). An siffanta yanayin saman perovskite bayan maganin oxalic acid ta hanyar ma'aunin X-ray photoelectron spectroscopy (XPS), kamar yadda aka nuna a cikin Hoto na 2e–g. A cikin Hoto na 2e, saman C 1s yana kusa da 284.8 eV da 288.5 eV suna cikin takamaiman siginar CC da FA, bi da bi. Idan aka kwatanta da membrane na sarrafawa, membrane na LOS ya nuna ƙarin kololuwa a 289.2 eV, wanda aka danganta da C2O42-. Bakan O1s na LOS perovskite yana nuna kololuwar O1s guda uku daban-daban a cikin sinadarai a 531.7 eV, 532.5 eV, da 533.4 eV, wanda ya dace da COO da aka cire, C=O na ƙungiyoyin oxalate marasa cikewa 30 da atoms O na bangaren OH (Hoto na 2e). )). Ga samfurin sarrafawa, an lura da ƙaramin kololuwar O1s kawai, wanda za'a iya danganta shi da iskar oxygen da aka narkar a saman. Halayen membrane na sarrafawa na Pb 4f7/2 da Pb 4f5/2 suna a 138.4 eV da 143.3 eV, bi da bi. Mun lura cewa LOS perovskite yana nuna canjin kololuwar Pb na kusan 0.15 eV zuwa makamashin ɗaurewa mafi girma, yana nuna hulɗa mai ƙarfi tsakanin atoms na C2O42- da Pb (Hoto na 2g).
Hotunan SEM na fina-finan sarrafawa da b LOS perovskite, saman kallo. c Babban ƙudurin watsa electron watsawa na giciye-sashe (HR-TEM) na fina-finan sarrafawa da d LOS perovskite. Babban ƙudurin XPS na fina-finan e C 1s, f O 1s da g Pb 4f perovskite. Ana bayar da bayanan tushe a cikin nau'in fayilolin bayanai na tushe.
A bisa ga sakamakon DFT, an yi hasashen cewa lahani na VI da ƙaura ta I cikin sauƙi suna haifar da sauyawar mataki daga α zuwa δ. Rahotannin da suka gabata sun nuna cewa I2 yana fitowa da sauri daga fina-finan perovskite da aka yi da PC yayin nutsewa cikin haske bayan fallasa fina-finan ga haske da matsin zafi31,32,33. Don tabbatar da tasirin daidaita gubar oxalate akan matakin α na perovskite, mun nutsar da fina-finan sarrafawa da LOS perovskite a cikin kwalaben gilashi masu haske waɗanda ke ɗauke da toluene, bi da bi, sannan muka haskaka su da hasken rana 1 na tsawon awanni 24. Mun auna shan maganin toluene na ultraviolet da haske mai gani (UV-Vis)., kamar yadda aka nuna a Hoto na 3a. Idan aka kwatanta da samfurin sarrafawa, an lura da ƙarancin ƙarfin sha na I2 a yanayin LOS-perovskite, wanda ke nuna cewa ƙaramin LOS na iya hana sakin I2 daga fim ɗin perovskite yayin nutsewa cikin haske. Hotunan fina-finan sarrafawa na tsufa da LOS perovskite an nuna su a cikin saitin Figures 3b da c. LOS perovskite har yanzu baƙar fata ce, yayin da yawancin fim ɗin sarrafawa ya zama rawaya. An nuna siginar shaƙar UV-wanda ake iya gani na fim ɗin da aka nutse a cikin Hoto na 3b, c. Mun lura cewa shaƙar da ta dace da α a cikin fim ɗin sarrafawa ta ragu a bayyane. An yi ma'aunin X-ray don yin rikodin juyin halittar tsarin lu'ulu'u. Bayan awanni 24 na haske, perovskite mai sarrafawa ya nuna siginar δ mai ƙarfi (11.8°), yayin da LOS perovskite har yanzu yana da kyakkyawan yanayin baƙi (Hoto na 3d).
Siffar shaƙar toluene da ake iya gani ta UV wadda aka nutsar da fim ɗin sarrafawa da fim ɗin LOS a ƙarƙashin hasken rana 1 na tsawon awanni 24. Siffar shaƙar tana nuna kwalba inda aka nutsar da kowane fim a cikin adadin toluene daidai gwargwado. b Siffar shaƙar UV-Vis na fim ɗin sarrafawa da fim ɗin LOS kafin da kuma bayan awanni 24 na nutsarwa a ƙarƙashin hasken rana 1. Siffar shaƙar tana nuna hoton fim ɗin gwaji. d Tsarin watsa X-ray na sarrafawa da finafinan LOS kafin da kuma bayan awanni 24 na fallasa. Hotunan SEM na fim ɗin sarrafawa da fim ɗin LOS bayan awanni 24 na fallasa. Ana bayar da bayanan tushe ta hanyar fayilolin bayanai na tushe.
Mun yi gwajin na'urar daukar hoton lantarki ta hanyar amfani da na'urar daukar hoton lantarki (SEM) don lura da canje-canjen tsarin fim ɗin perovskite bayan awanni 24 na haske, kamar yadda aka nuna a cikin Hotuna na 3e,f. A cikin fim ɗin sarrafawa, an lalata manyan hatsi kuma an mayar da su ƙananan allurai, wanda ya yi daidai da yanayin samfurin δ-phase FAPbI3 (Hoto na 3e). Ga fina-finan LOS, ƙwayoyin perovskite suna cikin kyakkyawan yanayi (Hoto na 3f). Sakamakon ya tabbatar da cewa asarar I yana haifar da sauyawa daga yanayin baƙi zuwa yanayin rawaya, yayin da PbC2O4 ke daidaita yanayin baƙi, yana hana asarar I. Tunda yawan gurɓataccen wuri a saman ya fi girma fiye da na yawan hatsi,34 wannan matakin yana iya faruwa a saman hatsi. a lokaci guda yana sakin iodine kuma yana samar da VI. Kamar yadda DFT ta annabta, LOS na iya hana samuwar lahani na VI kuma yana hana ƙaura na ions na I zuwa saman perovskite.
Bugu da ƙari, an yi nazarin tasirin layin PbC2O4 akan juriyar danshi na fina-finan perovskite a cikin iskar yanayi (danshin da ya dace da 30-60%). Kamar yadda aka nuna a cikin Ƙarin Hoto na 9, LOS perovskite har yanzu yana da baƙi bayan kwana 12, yayin da fim ɗin sarrafawa ya zama rawaya. A cikin ma'aunin XRD, fim ɗin sarrafawa yana nuna babban kololuwa a 11.8° wanda ya dace da matakin δ na FAPbI3, yayin da LOS perovskite ke riƙe da matakin α baƙi sosai (Karin Hoto na 10).
An yi amfani da hasken rana mai ƙarfi (PL) da hasken rana mai ƙarfi (TRPL) don nazarin tasirin passivation na gubar oxalate akan saman perovskite. A cikin Hoto na 4a ya nuna cewa fim ɗin LOS ya ƙara ƙarfin PL. A cikin hoton taswirar PL, ƙarfin fim ɗin LOS a duk faɗin yankin 10 × 10 μm2 ya fi na fim ɗin sarrafawa (Hoto na Ƙarin 11), yana nuna cewa PbC2O4 yana lalata fim ɗin perovskite gaba ɗaya. Rayuwar mai ɗaukar hoto ana ƙayyade ta hanyar kimanta lalacewar TRPL tare da aiki ɗaya mai faɗi (Hoto na 4b). Rayuwar mai ɗaukar hoto na fim ɗin LOS shine 5.2 μs, wanda ya fi tsayi fiye da fim ɗin sarrafawa tare da rayuwar mai ɗaukar hoto na 0.9 μs, yana nuna raguwar haɗuwa mara radiation a saman.
Tsarin PL mai tsayi da b-spectra na fim ɗin perovskite na wucin gadi akan gilashin da aka yi amfani da su. c Lanƙwasa na SP na na'urar (FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au). d Tsarin EQE da Jsc EQE da aka haɗa daga na'urar da ta fi inganci. d Dogaro da ƙarfin haske na na'urar perovskite akan zane na Voc. f Binciken MKRC na yau da kullun ta amfani da na'urar rami mai tsabta ta ITO/PEDOT:PSS/perovskite/PCBM/Au. VTFL shine matsakaicin ƙarfin cika tarko. Daga waɗannan bayanan mun ƙididdige yawan tarko (Nt). Ana bayar da bayanan tushe a cikin nau'in fayilolin bayanai na tushe.
Domin yin nazarin tasirin layin oxalate na gubar a kan aikin na'urar, an yi amfani da tsarin hulɗa na gargajiya na FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au. Muna amfani da formamidine chloride (FACl) a matsayin ƙari ga precursor na perovskite maimakon methylamine hydrochloride (MACl) don cimma ingantaccen aikin na'urar, tunda FACl na iya samar da ingantaccen ingancin lu'ulu'u da kuma guje wa gibin da ke tsakanin FAPbI335 (duba Ƙarin Hotuna 1 da 2 don cikakken kwatantawa). 12-14). An zaɓi IPA a matsayin maganin hana narkewa saboda yana samar da ingantaccen ingancin lu'ulu'u da kuma fifikon da aka fi so a cikin fina-finan perovskite idan aka kwatanta da diethyl ether (DE) ko chlorobenzene (CB)36 (Ƙarin Hotuna 15 da 16). An inganta kauri na PbC2O4 a hankali don daidaita daidaiton lahani da jigilar caji ta hanyar daidaita yawan oxalic acid (Ƙarin Hoto 17). An nuna hotunan SEM na sassan da aka gyara na na'urorin sarrafawa da LOS a cikin Hoto na Ƙari na 18. An nuna lanƙwasa na yau da kullun na yawan wutar lantarki (CD) don na'urorin sarrafawa da LOS a cikin Hoto na 4c, kuma an ba da sigogin da aka cire a cikin Tebur na Ƙari na 3. Mafi girman ingancin canza wutar lantarki (PCE) ƙwayoyin sarrafawa 23.43% (22.94%), Jsc 25.75 mA cm-2 (25.74 mA cm-2), Voc 1.16 V (1.16 V) da kuma sake dubawa (gaba). Ma'aunin cikawa (FF) shine 78.40% (76.69%). Matsakaicin PCE LOS PSC shine 25.39% (24.79%), Jsc shine 25.77 mA cm-2, Voc shine 1.18 V, FF shine 83.50% (81.52%) daga baya (Scan gaba zuwa). Na'urar LOS ta sami ingantaccen aikin photovoltaic na 24.92% a cikin dakin gwaje-gwaje na photovoltaic na ɓangare na uku amintacce (Hoto na Ƙarin 19). Ingancin ƙididdigar waje (EQE) ya ba da haɗin Jsc na 24.90 mA cm-2 (ikon sarrafawa) da 25.18 mA cm-2 (LOS PSC), bi da bi, wanda ya yi daidai da Jsc da aka auna a cikin daidaitaccen bakan AM 1.5 G (Hoto na .4d). An nuna rarraba ƙididdiga na PCEs da aka auna don sarrafawa da LOS PSCs a cikin Hoto na Ƙarin 20.
Kamar yadda aka nuna a Hoto na 4e, an ƙididdige dangantakar da ke tsakanin Voc da ƙarfin haske don nazarin tasirin PbC2O4 akan haɗakar saman da aka taimaka wa tarko. Gangar layin da aka sanya wa na'urar LOS shine 1.16 kBT/sq, wanda ya yi ƙasa da gangaren layin da aka sanya wa na'urar sarrafawa (1.31 kBT/sq), yana tabbatar da cewa LOS yana da amfani don hana haɗakar saman ta hanyar decoys. Muna amfani da fasahar iyakance wutar lantarki ta sararin samaniya (SCLC) don auna yawan lahani na fim ɗin perovskite ta hanyar auna halayen IV mai duhu na na'urar rami (ITO/PEDOT:PSS/perovskite/spiro-OMeTAD/Au) kamar yadda aka nuna a cikin hoton. 4f Nuna. Ana ƙididdige yawan tarko ta hanyar dabarar Nt = 2ε0εVTFL/eL2, inda ε shine ma'aunin dielectric na fim ɗin perovskite, ε0 shine ma'aunin dielectric na injin, VTFL shine ƙarfin lantarki mai iyaka don cike tarkon, e shine caji, L shine kauri na fim ɗin perovskite (650 nm). An ƙididdige yawan lahani na na'urar VOC zuwa 1.450 × 1015 cm–3, wanda ya yi ƙasa da yawan lahani na na'urar sarrafawa, wanda shine 1.795 × 1015 cm–3.
An gwada na'urar da ba a rufe ba a wurin wutar lantarki mafi girma (MPP) a ƙarƙashin cikakken hasken rana a ƙarƙashin nitrogen don duba daidaiton aikinta na dogon lokaci (Hoto na 5a). Bayan awanni 550, na'urar LOS ta ci gaba da riƙe da kashi 92% na mafi girman ingancinta, yayin da aikin na'urar sarrafawa ya ragu zuwa kashi 60% na aikinta na asali. An auna rarrabawar abubuwan da ke cikin tsohuwar na'urar ta hanyar amfani da na'urar auna yawan ion na biyu (ToF-SIMS) (Hoto na 5b, c). Ana iya ganin tarin iodine mai yawa a yankin sarrafa zinare na sama. Yanayin kariyar iskar gas mara aiki ya haɗa da abubuwan da ke lalata muhalli kamar danshi da iskar oxygen, yana nuna cewa hanyoyin ciki (watau ƙaura ion) suna da alhakin. Dangane da sakamakon ToF-SIMS, an gano I- da AuI2-ions a cikin na'urar lantarki ta Au, wanda ke nuna yaduwar I daga perovskite zuwa Au. Ƙarfin siginar I- da AuI2-ions a cikin na'urar sarrafawa ya ninka na samfurin VOC sau 10. Rahotannin da suka gabata sun nuna cewa kwararar ion na iya haifar da raguwar saurin kwararar iskar spiro-OMeTAD da kuma lalata sinadarai na saman layin lantarki, wanda hakan ke lalata hulɗar da ke tsakanin na'urar da maganin chlorobenzene. Sannan muka bayyana fim ɗin ta amfani da rarrafewar X-ray diffraction (GIXRD) (Hoto na 5d). Sakamakon ya nuna cewa fim ɗin sarrafawa yana da kololuwar diffraction a fili a 11.8°, yayin da babu wani sabon kololuwar diffraction da ya bayyana a cikin samfurin LOS. Sakamakon ya nuna cewa manyan asarar ions na I a cikin fim ɗin sarrafawa suna haifar da samar da matakin δ, yayin da a cikin fim ɗin LOS wannan tsari yana da ƙarfi a bayyane.
Sa'o'i 575 na ci gaba da bin diddigin na'urar da ba a rufe ba a cikin yanayin nitrogen da hasken rana 1 ba tare da matattarar UV ba. Rarraba ToF-SIMs na b I- da c AuI2- ions a cikin na'urar sarrafa LOS MPP da na'urar tsufa. Inuwar rawaya, kore da lemu sun yi daidai da Au, Spiro-OMeTAD da perovskite. d GIXRD na fim ɗin perovskite bayan gwajin MPP. Ana bayar da bayanan tushe a cikin nau'in fayilolin bayanai na tushe.
An auna ƙarfin lantarki da ya dogara da zafin jiki don tabbatar da cewa PbC2O4 na iya hana ƙaurar ion (Karin Hoto na 21). Ana ƙayyade kuzarin kunnawa (Ea) na ƙaurar ion ta hanyar auna canjin yanayin lantarki (σ) na fim ɗin FAPbI3 a yanayin zafi daban-daban (T) da kuma amfani da alaƙar Nernst-Einstein: σT = σ0exp(−Ea/kBT), inda σ0 yake mai dorewa, kB shine madaidaicin Boltzmann. Mun sami ƙimar Ea daga gangaren ln(σT) idan aka kwatanta da 1/T, wanda shine 0.283 eV don sarrafawa da 0.419 eV don na'urar LOS.
A taƙaice, mun samar da tsarin nazari don gano hanyar lalata FAPbI3 perovskite da tasirin lahani daban-daban akan shingen makamashi na canjin yanayin α-δ. Daga cikin waɗannan lahani, ana hasashen lahani na VI a ka'ida cewa zai iya haifar da sauyawar lokaci cikin sauƙi daga α zuwa δ. An gabatar da wani Layer mai yawa na PbC2O4 wanda ba ya narkewa cikin ruwa kuma mai karko a sinadarai don daidaita yanayin α na FAPbI3 ta hanyar hana samuwar guraben I da ƙaura na ions na I. Wannan dabarar tana rage haɗuwar da ba ta da radiative tsakanin fuskoki, tana ƙara ingancin ƙwayoyin rana zuwa 25.39%, kuma tana inganta kwanciyar hankali na aiki. Sakamakonmu yana ba da jagora don cimma ingantaccen tsari da kwanciyar hankali na formamidine PSCs ta hanyar hana canjin yanayin α zuwa δ da lahani ya haifar.
An sayi titanium(IV) isopropoxide (TTIP, 99.999%) daga Sigma-Aldrich. An sayi hydrochloric acid (HCl, 35.0–37.0%) da ethanol (anhydrous) daga masana'antar sinadarai ta Guangzhou. An sayi SnO2 (15 wt% tin(IV) oxide colloidal dispersion) daga Alfa Aesar. An sayi Lead(II) iodide (PbI2, 99.99%) daga TCI Shanghai (China). An sayi Formamidine iodide (FAI, ≥99.5%), formamidine chloride (FACl, ≥99.5%), methylamine hydrochloride (MACl, ≥99.5%), 2,2′,7,7′-tetrakis-(N, N-di-p) )-methoxyaniline)-9,9′-spirobifluorene (Spiro-OMeTAD, ≥99.5%), lithium bis(trifluoromethane)sulfonylamide (Li-TFSI, 99.95%), 4-tert-butylpyridine (tBP, 96%) daga Kamfanin Fasaha na Xi'an Polymer Light (China). N,N-dimethylformamide (DMF, 99.8%), dimethyl sulfoxide (DMSO, 99.9%), isopropyl alcohol (IPA, 99.8%), chlorobenzene (CB, 99.8%), acetonitrile (ACN). An saya daga Sigma-Aldrich. An sayi Oxalic acid (H2C2O4, 99.9%) daga Macklin. An yi amfani da duk sinadarai kamar yadda aka karɓa ba tare da wani gyare-gyare ba.
An tsaftace substrates na ITO ko FTO (1.5 × 1.5 cm2) ta hanyar amfani da sabulun wanki, acetone, da ethanol na tsawon minti 10, bi da bi, sannan a busar da su a ƙarƙashin rafin nitrogen. An sanya wani katafaren shinge na TiO2 mai yawa a kan substrates na FTO ta amfani da maganin titanium diisopropoxybis (acetylacetonate) a cikin ethanol (1/25, v/v) da aka ajiye a 500 °C na tsawon minti 60. An narkar da watsawar colloidal na SnO2 da ruwan da aka cire a cikin rabon girma na 1:5. A kan wani abu mai tsabta da aka yi wa magani da UV ozone na tsawon minti 20, an saka wani siririn fim na SnO2 nanoparticles a 4000 rpm na tsawon daƙiƙa 30 sannan a sanyaya a 150 °C na tsawon minti 30. Don maganin precursor na perovskite, an narkar da 275.2 mg FAI, 737.6 mg PbI2 da FACl (20 mol%) a cikin gaurayen sinadaran DMF/DMSO (15/1). An shirya layin perovskite ta hanyar yin amfani da 40 μL na maganin precursor na perovskite a saman layin SnO2 da aka yi wa UV-ozone magani a 5000 rpm a cikin iska mai yanayi na tsawon daƙiƙa 25. Bayan daƙiƙa 5, an sauke 50 μL na maganin MACl IPA (4 mg/mL) cikin sauri a kan substrate a matsayin maganin hana narkewa. Sannan, an rufe fina-finan da aka shirya sabo a 150°C na tsawon minti 20 sannan a 100°C na tsawon minti 10. Bayan sanyaya fim ɗin perovskite zuwa zafin ɗaki, an sanya maganin H2C2O4 (1, 2, 4 mg da aka narkar a cikin 1 mL IPA) a 4000 rpm na tsawon daƙiƙa 30 don ya yi aiki a saman perovskite. An yi amfani da maganin spiro-OMeTAD ta hanyar haɗa spiro-OMeTAD 72.3 mg, CB 1 ml, 27 µl tBP da 17.5 µl Li-TFSI (520 mg a cikin acetonitrile 1 ml) a kan fim ɗin a 4000 rpm cikin daƙiƙa 30. A ƙarshe, an cire wani Layer Au mai kauri 100 nm a cikin injin tsabtace iska a cikin ƙimar 0.05 nm/s (0~1 nm), 0.1 nm/s (2~15 nm) da 0.5 nm/s (16~100 nm).
An auna aikin SC na ƙwayoyin hasken rana na perovskite ta amfani da na'urar Keithley 2400 a ƙarƙashin hasken na'urar kwaikwayo ta hasken rana (SS-X50) a ƙarfin haske na 100 mW/cm2 kuma an tabbatar da shi ta amfani da ƙwayoyin hasken rana na silicon da aka daidaita. Sai dai idan an faɗi akasin haka, an auna lanƙwasa SP a cikin akwatin safar hannu mai cike da nitrogen a zafin ɗaki (~25°C) a cikin yanayin duba gaba da baya (matakin ƙarfin lantarki 20 mV, lokacin jinkiri 10 ms). An yi amfani da abin rufe fuska na inuwa don tantance yanki mai tasiri na 0.067 cm2 don PSC da aka auna. An gudanar da ma'aunin EQE a cikin iska ta amfani da tsarin PVE300-IVT210 (Industrial Vision Technology(s) Pte Ltd) tare da hasken monochromatic da aka mayar da hankali kan na'urar. Don kwanciyar hankali na na'ura, an gudanar da gwajin ƙwayoyin hasken rana marasa lulluɓe a cikin akwatin safar hannu na nitrogen a matsin lamba 100 mW/cm2 ba tare da matatar UV ba. Ana auna ToF-SIMS ta amfani da SIMS nanoTOFII na tashi na PHI. An samo zurfin bayanin martaba ta amfani da bindigar Ar ion mai ƙarfin 4 kV tare da yanki na 400 × 400 µm.
An yi ma'aunin hasken X-ray photoelectron spectroscopy (XPS) akan tsarin kimiyya na Thermo-VG (ESCALAB 250) ta amfani da monochromatized Al Kα (don yanayin XPS) a matsin lamba na 5.0 × 10–7 Pa. An yi amfani da na'urar daukar hoto ta ... An auna hotunan taswirar PL ta amfani da tsarin Horiba LabRam Raman na HR Evolution. An yi amfani da tsarin Thermo-Fisher Nicolet NXR 9650 wajen auna hotunan infrared spectroscopy (FTIR).
A cikin wannan aikin, muna amfani da hanyar samfurin hanyar SSW don nazarin hanyar sauyawar mataki daga α-phase zuwa δ-phase. A cikin hanyar SSW, ana ƙayyade motsi na saman makamashi mai yuwuwa ta hanyar alkiblar yanayin laushi na bazuwar (na biyu da aka samo), wanda ke ba da damar yin cikakken bincike da manufa na saman makamashi mai yuwuwa. A cikin wannan aikin, ana yin samfurin hanya akan supercell na atom 72, kuma ana tattara nau'i-nau'i sama da 100 na farko/na ƙarshe (IS/FS) a matakin DFT. Dangane da saitin bayanai na IS/FS, ana iya tantance hanyar da ke haɗa tsarin farko da tsarin ƙarshe tare da daidaito tsakanin atoms, sannan ana amfani da motsi na hanyoyi biyu tare da saman naúrar mai canzawa don tantance hanyar yanayin sauyawa cikin sauƙi. (VK-DESV). Bayan neman yanayin sauyawa, ana iya tantance hanyar da ke da mafi ƙarancin shinge ta hanyar tsara shingen makamashi.
An yi duk lissafin DFT ta amfani da VASP (sigar 5.3.5), inda hulɗar electron-ion na atoms na C, N, H, Pb, da I an wakilta su ta hanyar tsarin haɓakar raƙuman ruwa (PAW). An bayyana aikin haɗin musayar ta hanyar kimantawar gradient gabaɗaya a cikin parametrization na Perdue-Burke-Ernzerhoff. An saita iyakar kuzari don raƙuman jirgin sama zuwa 400 eV. Grid ɗin k-point na Monkhorst-Pack yana da girman (2 × 2 × 1). Ga duk tsarin, an inganta matsayin lattice da atomic gaba ɗaya har sai matsakaicin ɓangaren damuwa ya kasance ƙasa da 0.1 GPa kuma matsakaicin ƙarfin bangaren ya kasance ƙasa da 0.02 eV/Å. A cikin samfurin saman, saman FAPbI3 yana da layuka 4, ƙasan yana da atoms masu tsayayye waɗanda ke kwaikwayon jikin FAPbI3, kuma manyan layuka uku na iya motsawa cikin 'yanci yayin tsarin ingantawa. Layin PbC2O4 yana da kauri 1 ML kuma yana kan saman I-terminal na FAPbI3, inda Pb ke daure zuwa 1 I da 4 O.
Don ƙarin bayani game da tsarin binciken, duba Takaitaccen Rahoton Fayil na Halitta wanda ke da alaƙa da wannan labarin.
Duk bayanan da aka samu ko aka yi nazari a kansu a lokacin wannan binciken an haɗa su a cikin labarin da aka buga, da kuma bayanan tallafi da fayilolin bayanai na asali. Bayanan da aka gabatar a cikin wannan binciken suna samuwa a https://doi.org/10.6084/m9.figshare.2410016440. An samar da bayanan tushe don wannan labarin.
Green, M. da sauransu. Teburin Inganta Ƙarfin Hasken Rana (bugu na 57). shiri. Na'urar daukar hoto. Albarkatu. aikace-aikace. 29, 3–15 (2021).
Parker J. da sauransu. Sarrafa girman yadudduka na perovskite ta amfani da alkyl ammonium chlorides masu canzawa. Nature 616, 724–730 (2023).
Zhao Y. da sauransu. Rashin aiki (PbI2)2RbCl yana daidaita fina-finan perovskite don ƙwayoyin hasken rana masu inganci. Kimiyya 377, 531–534 (2022).
Tan, K. da sauransu. Kwayoyin hasken rana na perovskite da aka juya ta amfani da dimethylacridinyl dopant. Nature, 620, 545–551 (2023).
Han, K. da sauransu. Fomamidine gubar iodide mai lu'ulu'u guda ɗaya (FAPbI3): fahimtar halayen tsari, gani da lantarki. Karin magana. Matt. 28, 2253–2258 (2016).
Massey, S. da sauransu. Daidaitawar yanayin baƙar fata na perovskite a cikin FAPbI3 da CsPbI3. AKS Energy Communications. 5, 1974–1985 (2020).
Kai, JJ, da sauransu. Ingancin ƙwayoyin hasken rana na perovskite ta hanyar ingantaccen tsarin kula da masu ɗaukar kaya. Nature 590, 587–593 (2021).
Saliba M. da sauransu. Haɗa rubidium cations cikin ƙwayoyin hasken rana na perovskite yana inganta aikin photovoltaic. Kimiyya 354, 206–209 (2016).
Saliba M. da sauransu. Kwayoyin hasken rana na cesium perovskite guda uku: ingantaccen kwanciyar hankali, sake haifuwa da kuma ingantaccen aiki. muhallin makamashi. kimiyya. 9, 1989–1997 (2016).
Cui X. da sauransu. Ci gaban da aka samu kwanan nan a cikin daidaita yanayin FAPbI3 a cikin ƙwayoyin hasken rana na perovskite masu aiki mai ƙarfi Sol. RRL 6, 2200497 (2022).
Delagetta S. da sauransu. Rabawar lokaci mai ma'ana ta hanyar photoinduced photoinduced na gaurayen halide na halitta-inorganic perovskites. Nat. sadarwa. 8, 200 (2017).
Slotcavage, DJ da sauransu. Rabawar lokaci mai haske a cikin masu shan halide perovskite. AKS Energy Communications. 1, 1199–1205 (2016).
Chen, L. da sauransu. Daidaiton lokaci na ciki da kuma bambancin da ke tsakanin formamidine da kuma lu'ulu'u guda ɗaya na formamidine. Anjiva. Sinadaran. Ƙasashen Duniya. Edita. 61. e202212700 (2022).
Duinsti, EA da sauransu. Fahimci rugujewar methylenediammonium da rawar da take takawa wajen daidaita yanayin lead triiodide formamidine. J. Chem. Bitch. 18, 10275–10284 (2023).
Lu, HZ da sauransu. Tarin tururi mai inganci da kwanciyar hankali na ƙwayoyin hasken rana na perovskite masu duhu FAPbI3. Kimiyya 370, 74 (2020).
Doherty, TAS da sauransu. Perovskites masu tsauri waɗanda ke da karkata daga octahedral halide suna danne samuwar matakai na gida tare da iyakantattun halaye. Kimiyya 374, 1598–1605 (2021).
Ho, K. da sauransu. Hanyoyin canzawa da lalata ƙwayoyin formamidine da cesium da lead iodide perovskites ƙarƙashin tasirin danshi da haske. AKS Energy Communications. 6, 934–940 (2021).
Zheng J. da sauransu. Ci gaban anions na pseudohalide don ƙwayoyin hasken rana na perovskite na α-FAPbI3. Nature 592, 381–385 (2021).