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Defect passivation ni ki tiyo kwede me medo tic pa lead triiodide perovskite solar cells, ento adwogi pa defects mapat pat i kom α-phase stability pwod pe nen maber; Kany, kun wa tiyo ki lok ma mako rwom me tic, wa nongo pi tyen mukwongo yoo me balo pa formamidine lead triiodide perovskite ki i α-phase me oo i δ-phase ki kwan adwogi pa peko ma pat pat i kom gin ma gengo teko me loko rwom me rwom. Adwogi me temo ni nyutu ni iodine vacancies twero kelo balo pien gi dwoko piny teko ma gengo α-δ phase transition ki tye ki teko ma lapiny loyo i kom perovskite. Kelo gin ma ki lwongo ni lead oxalate ma pe romo gonyo i pii i kom perovskite ni gengo balo pa α-phase, gengo ngwec ki doko pa iodine. Medo ikom meno, yoo man dwoko piny rwom me rwate pa jami ma pe nen ki medo tic pa solar cell nio wa i 25.39% (ki moko 24.92%). Gin ma ki yubu ni twero gwoko tic ne macon ma romo 92% ingee tic ki teko ma malo pi cawa 550 i te yamo ma ki lwongo ni 1.5 G.
Kit ma teko me tic kwede (PCE) pa perovskite solar cells (PSCs) oo i rwom ma malo ma oo 26%1. Cake i mwaka 2015, PSCs me kare ni gu maro formamidine triiodide perovskite (FAPbI3) ma calo gin ma kwanyo lero pien tye ki rwom me lyeto maber ki bandgap ma cok ki rwom me Shockley-Keisser me 2,3,4. Ki cwer cwiny, FAPbI3 films thermodynamically gi kato ki i alokaloka me rwom me α phase me doko yellow non-perovskite δ phase i rwom me lyeto me ot5,6. Me gengo yub pa delta phase, jami mapol ma ki lwongo ni perovskite compositions ki oyubu. Yo ma pol loyo me cobo peko eni tye me rubu FAPbI3 ki methyl ammonium (MA+), cesium (Cs+) ki bromide (Br-) ions7,8,9. Ento, hybrid perovskites gi deno can pi bandgap broading ki photoinduced phase separation, ma balo tic ki rwom me tic pa PSCs10,11,12.
Kwan ma ki tiyo cok cok ni onyutu ni gin ma ki lwongo ni pure single crystal FAPbI3 ma pe ki keto iye gin mo kiken tye ki rwom maber me cung matek pi crystallinity ne maber ki goro ne manok13,14. Pi meno, dwoko piny peko kun ki medo rwom me dongo pa FAPbI3 obedo yoo ma pire tek me nongo PSCs2,15 ma tiyo maber ki ma cung matek. Ento, i kare me tic pa FAPbI3 PSC, balo ne i kom ma pe ki miito ma yellow hexagonal non-perovskite δ phase pud twero time16. Kit me tiimo ne pol kare cake i kom piny ki i wang jami ma pii, lyeto ki lero twero nongo ne pien tye kabedo mapol ma goro17. Pi meno, rwom me tic pa jami ma ki lwongo ni surface/grain passivation mitte me gwoko dul macol pa FAPbI318. Yoo mapol me juku peko, medo ki kelo perovskites ma rwom ne lapiny, acid-base Lewis molecules, ki ammonium halide salts, gu kelo alokaloka madit i formamidine PSCs19,20,21,22. Ki i kare ni, kwan weng gu keto cwiny gi i kom tic pa jami ma pat pat ma pe rwate i kit ma optoelectronic tye kwede calo carrier recombination, diffusion length ki band structure i solar cells22,23,24. Me labolle, lok ma mako rwom me tic pa jami (DFT) ki tiyo kwede me byeko teko me yubu ki rwom me teko me mako jami ma pat pat, ma kitiyo kwede me telo yub me tic pa passivation20,25,26. Ka wel jami ma obale odok piny, rwom me tic pa jami ni bedo maber. Ento, i formamidine PSCs, kit ma jami ma pat pat ma kelo peko i kom rwom me rwom ki rwom me teko pa mac omyera obed ma pat. Ki ngec ma wa tye kwede, niang matut i kom kit ma peko kelo kwede alokaloka me cubic to hexagonal (α-δ) ki tic pa surface passivation i kom rwom me α-FAPbI3 perovskite pud pe ki niang maber.
Kany, wa nyutu yoo me balo pa FAPbI3 perovskite ki i α-phase macol me doko δ-phase ma yelo ki kit ma jami ma pat pat ma balo teko pa α-to-δ-phase loko kwede kun wok ki i DFT. I kabedo ma odong, ma ki yubu oyotoyot i kare me yubu filim ki tic ki jami, ki byeko ni obi cako α-δ phase transition. Pi meno, wa keto gin ma pe romo gonyo i pii ki ma rwate ki jami ma ki lwongo ni lead oxalate (PbC2O4) i kom FAPbI3 kun wa wok ki i gin ma ki lwongo ni in situ reaction. Lead oxalate surface (LOS) gengo dongo pa I vacancies ki gengo wot pa I ions ka ki juku ki lyeto, lero, ki teko me mac. LOS ma aa ki iye dwoko piny rwom me rwate pa jami ma pe nen ki medo tic pa FAPbI3 PSC nio wa i 25.39% (ki moko ni 24.92%). Gin ma ki lwongo ni Unpackaged LOS device ni ogwoko 92% me tic ne macon ingee tic ki teko ma malo (MPP) pi cawa ma oo 550 i yamo ma ki poro (AM) me 1.5 G me radiation.
Wa cako timo kwan ma ki lwongo ni ab initio me nongo yoo ma FAPbI3 perovskite ni twero rweny kwede me loko ki i α phase me oo i δ phase. Ki i yub me loko dul ma ki ngeyo maber, kinongo ni loko ki i kom dul adek ma poko dul [PbI6] octahedron i cubic α-phase pa FAPbI3 me doko dul acel ma poko tung [PbI6] octahedron i hexagonal δ-phase pa FAPbI3 ki cobo. turo 9. Pb-I yubu dul ma rwate i rwom me acel (Int-1), ki rwom me teko ne oo 0.62 eV/cell, ma ki nyutu i cal 1a. Ka octahedron ni ki loko i yoo me [0\(\bar{1}\)1], gin ma ki lwongo ni hexagonal short chain ni dongo ki 1×1 nio wa i 1×3, 1×4 ki lacen donyo i δ phase. Kit ma yoo ni nen kwede tye (011)α//(001)δ + [100]α//[100]δ. Cake i kom cal ma ki poko iye teko, ki twero nongo ni inge keto δ dul pa FAPbI3 i rwom ma lubo ni, gin ma gengo teko ni tye piny loyo pa α dul ma ki loko, ma nyutu ni dul ma ki loko ni obi mede oyotoyot. Ki lok adaa, tyelo mukwongo me juku alokaloka me rwom ma malo pire tek ka wamito gengo rweny pa α-phase.
kit me loko dul ma aa ki tung lacuc me cito tung lacuc - dul FAPbI3 macol (α-dul), Pb-I bond cleavage mukwongo (Int-1) ki medo Pb-I bond cleavage (Int-2, Int -3 ki Int -4) ki yellow phase FAPbI3 (delta phase). b Gin ma gengo teko i kom α me δ ma ki loko i FAPbI3 ma lubu peko ma pat pat. Lain ma ki keto ni nyutu teko ma gengo gin ma ki lwongo ni ideal crystal (0.62 eV). c Teko me yubu gin ma pi rwate i kom lead perovskite. Abscissa axis obedo teko ma gengo α-δ phase transition, ki ordinate axis obedo teko me defect formation. Dul ma ki keto i kala macol, yellow ki green tye dul I (EB ma lapiny-FE ma malo), dul II (FE ma malo) ki dul III (EB ma lapiny-FE ma lapiny), kit meno. d Teko me yubu peko VI ki LOS pa FAPbI3 i kom gin ma ki temo. e I gengo cito pa ion i kom lok ki LOS pa FAPbI3. f – nyutu kit ma I ions (orange spheres) ki gLOS FAPbI3 (gray, lead; violet (orange), iodine (mobile iodine)) i gf control (tung lacuc: neno malo; tung lacuc: dul ma ki poko, brown); carbon; bulu ma ler - nitrogen; makwar - yamo; yamo; pink ma ler - hydrogen). Lok ma ki nongo ki iye ki miyo i kit me karatac ma ki nongo ki iye.
Wan dong wa kwano jami ma pat pat ma kelo peko (ma tye iye PbFA, IFA, PbI, ki IPb antisite occupancy; Pbi ki Ii interstitial atoms; ki VI, VFA, ki VPb vacancies), ma kitero calo gin ma pire tek. ma kelo rweny pa rwom me atom ki teko ma ki nyutu i cal 1b ki karatac me medo 1. I yo me miti, pe bal weny ma dwoko piny rwom me teko pa α-δ (lanyut 1b). Waye ni peko ma tye ki teko ma lapiny me yubu ki teko ma lapiny me loko rwom me α-δ kitero calo gin marac i kom rwom me rwom. Kit ma ki waco kwede con, kom ma tye ki lead pol kare ki ngeyo ni ber pi formamidine PSC27. Pi meno, wa keto tamwa i kom PbI2-terminated (100) ma tye i te jami ma tye ki lead madwong. Teko ma kelo peko i kom jami ma tye i kom jami ma tye i ngom ki nyutu i cal 1c ki karatac me medo 1. Malube ki teko ma gengo (EB) ki teko ma kelo alokaloka (FE), jami magi ki poko gi i dul adek. Kit I (EB ma lapiny-FE ma malo): Kadi bed ni IPb, VFA ki VPb gi dwoko piny teko ma gengo alokaloka me rwom, gin tye ki teko ma malo me yubu. Pi meno, waye ni jami ma kit magi tye ki adwogi manok i kom alokaloka me rwom pien pe gibedo ka dongo kare ki kare. Kit me II (EB ma malo): Pi rwom me α-δ ma ki medo i kom teko me loko, jami ma gengo kabedo PbI, IFA ki PbFA pe balo rwom me α-FAPbI3 perovskite. Kit me III (EB ma lapiny-FE ma lapiny): VI, Ii ki Pbi ma tye ki goro ma tye ki teko ma lapiny twero kelo balo pa dul macol. tutwale ka kimiyo FE ki EB VI ma piny loyo, waye ni yoo maber loyo tye me dwoko piny I vacancies.
Me dwoko piny VI, wa yubu dul ma pek pa PbC2O4 me medo rom pa FAPbI3. Ka kiporo ki jami ma ki lwongo ni organic halide salt passivators ma calo phenylethylammonium iodide (PEAI) ki n-octylammonium iodide (OAI), PbC2O4, ma pe ki mobile halogen ions, tye ma rwate ki jami ma ki lwongo ni chemical, pe twero gonyo i pii, ki twero rweny woko ka ki keto ne i tic. Gwoko yamo maber ki teko pa perovskite. Kit ma PbC2O4 twero gonyo kwede i pii tye 0.00065 g/L, ma tye piny loyo pa PbSO428. Ma pire tek loyo, dul LOS ma pek ki ma rom ki twero yubu mot mot i kom perovskite films kun kitiyo ki in situ reactions (nen piny kany). Watimo lanyut me DFT me rwate i kin FAPbI3 ki PbC2O4 kit ma ki nyutu kwede i cal me medo 1. Table me medo 2 nyutu teko me yubu peko inge keto LOS. Wanongo ni LOS pe medo teko me yubu VI ki 0.69-1.53 ​​eV (lanyut 1d), ento bene medo teko me tic pa I i kom ma ki cito iye ki kama ki kato iye (lanyut 1e). I dul mukwongo, I ions giwoto ki i kom perovskite, kun weko VI ions i rwom me lattice ki teko ma gengo 0.61 eV. Iyonge kelo LOS, pi adwogi pa steric hindrance, teko me tic pi wot pa I ions mede. 1.28 eV. I kare me ngwec pa I ions ma aa ki i kom perovskite, teko ma gengo i VOC bene tye malo loyo i kom ma ki temo (Fig. 1e). cal ma nyutu kit ma I ion giwoto kwede i control ki LOS FAPbI3 ki nyutu gi i cal 1 f ki g, kit meno. Adwogi me temo ni nyutu ni LOS twero gengo dongo pa VI ki loko pa I, ma gengo dongo pa α me δ.
Kit ma oxalic acid ki FAPbI3 perovskite rwate kwede ki temo. Iyonge rubu gin ma ki lwongo ni oxalic acid ki FAPbI3, wel ma dit pa jami ma ki lwongo ni white precipitate odongo, ma ki nyutu i cal me medo 2. Gin ma ki yubu ki buru ni ki ngeyo ni obedo gin ma ki lwongo ni PbC2O4 kun kitiyo ki X-ray diffraction (XRD) (cal me medo 3) ki Fourier transform infrared spectroscopy (FT SIR) (cal me medo 4). Wanongo ni oxalic acid twero gonyo i isopropyl alcohol (IPA) i rwom me lyeto me ot ki gonyo ne ma romo 18 mg/mL, ma ki nyutu i cal me 5. Man miyo tic ma lubo bedo yot pien IPA, ma calo gin ma ki tiyo kwede me juku, pe balo perovskite layer i kare manok. Pi meno, ka ki keto gin ma ki lwongo ni perovskite i pii ma ki lwongo ni oxalic acid onyo ki keto oxalic acid i kom gin ma ki lwongo ni perovskite, ki twero nongo PbC2O4 ma tidi ki ma pek oyotoyot i kom gin ma ki lwongo ni perovskite ma lubu kit ma ki kwano kwede: H2C2O4 + FAPI3 = PbI3 + FAIO4 FAI ki twero juku ne i IPA ki dong ki kwanyo ne i kare me tedo. Pek pa LOS ki twero doro ki kare me tic ki dwong pa gin ma okelo.
Cal ma ki kwanyo ki i Scanning electron microscopy (SEM) pa gin ma ki lwongo ni control ki LOS perovskite films ki nyutu gi i cal 2a,b. Adwogi ni nyutu ni kit ma kom perovskite nen kwede ki gwoko maber, ki wel jami matino tino mapol ki keto i kom nyig cam, ma omyera onyut PbC2O4 ma ki yubu ki i kom gin ma ki lwongo ni in-situ reaction. Gin ma ki lwongo ni LOS perovskite film ni tye ki kom ma pwot manok (lanyut me 6) ki rwom me rwate ki pii ma lac ka kiporo ki gin ma ki lwongo ni control film (lanyut me 7). Ki tiyo ki jami ma ki lwongo ni High-resolution transverse transmission electron microscopy (HR-TEM) me poko kin dul kom ma ki yubu ni. Ka kiporo ki gin ma ki lwongo ni control film (Fig. 2c), gin ma rwate ki ma pek ma tye ki pek ma romo 10 nm nen maber i kom LOS perovskite (Fig. 2d). Nono high-angle annular dark-field scanning electron microscopy (HAADF-STEM) me neno ka ma PbC2O4 ki FAPbI3 gi rwate kwede, bedo tye pa FAPbI3 ki dul ma pe nen pa PbC2O4 nen maber (Cal ma ki medo 8). Kit ma kom perovskite ni tye kwede i nge tic ki oxalic acid ni ki nyutu ki X-ray photoelectron spectroscopy (XPS), ma ki nyutu i cal 2e-g. I cal 2e, C 1s ma tye malo ma romo 284.8 eV ki 288.5 eV tye pi CC ki FA ma ki ngeyo, kit meno. Ka kiporo ki dul ma ki lwongo ni control membrane, LOS membrane onyutu rwom ma malo i 289.2 eV, ma ki keto i C2O42-. O 1s spectrum pa LOS perovskite nyutu O 1s adek ma pat pat ma tye i 531.7 eV, 532.5 eV, ki 533.4 eV, ma rwate ki deprotonated COO, C=O pa intact oxalate groups 30 ki O atoms me OH component (Fig. 2). )). Pi lanyut ma ki temo, O 1s matidi keken aye ki neno, ma ki twero keto i kom yamo ma ki nongo i kom ngom. Kit ma kom ma ki lwongo ni control membrane pa Pb 4f7/2 ki Pb 4f5/2 tye i 138.4 eV ki 143.3 eV, kit meno. Wa neno ni LOS perovskite nyutu alokaloka pa Pb peak ma romo 0.15 eV me rwate ki teko ma malo, ma nyutu ni rwate matek i kin C2O42- ki Pb atoms (Fig. 2g).
a cal me SEM me tic ki b LOS perovskite films, neno malo. c Gin ma ki lwongo ni High-resolution cross-sectional transmission electron microscopy (HR-TEM) me neno ki d LOS perovskite films. XPS ma ki neno maber pa e C 1s, f O 1s ki g Pb 4f perovskite films. Lok ma ki nongo ki iye ki miyo i kit me karatac ma ki nongo ki iye.
Malube ki adwogi me DFT, ki byeko ni VI ma obale ki I ma obale kelo alokaloka ki i α me doko δ. Ripot macon onyutu ni I2 ki gonyo oyot ki i PC-based perovskite films i kare me photoimmersion ingee keto filim ni i lero ki lyeto31,32,33. Me moko teko pa lead oxalate i kom α-phase pa perovskite, wa keto control ki LOS perovskite films i cupa ma ki yubu ki gilaci ma tye ki toluene, kit meno, ki dong wa keto gi ki lero ceng 1 pi cawa 24. Wa pimo rwom me mako pa mac ma ki lwongo ni ultraviolet ki lero ma nen (UV-Vis). ) toluene solution, ma ki nyutu i cal 3a. Ka kiporo ki labol ma ki temo, I2 ma nok tutwal ma ki nongo i kom LOS-perovskite, ma nyutu ni compact LOS twero gengo gonyo I2 ki i perovskite film i kare me keto i pii. Cal pa jami ma otii ki LOS perovskite ki nyutu gi i cal 3b ki c. LOS perovskite pud tye macol, ma nongo pol pa gin ma ki lwongo ni control film ni olokke odoko yellow. Kit ma UV-ma nen kwede ma mako gin ma ki keto i pii ni ki nyutu i cal. 3b, c. Wa neno ni rwom me nongo ma rwate ki α i filim ma ki temo ni odok piny. Kitimo pimo X-ray me coyo kit ma jami ma ki lwongo ni crystal ni odongo kwede. Iyonge cawa 24 me lero, gin ma ki lwongo ni control perovskite onyutu lanyut ma yellow δ-phase (11.8°), kun LOS perovskite pud tye ka gwoko phase macol maber (lanyut 3d).
UV-visible absorption spectra me toluene solutions ma ki keto iye gin ma ki lwongo ni control film ki LOS film ma ki keto i te lero me ceng 1 pi cawa 24. Gin ma ki keto ni nyutu gin ma ki keto iye filim acel acel i dwonge pa toluene ma rom. b UV-Vis absorption spectra me control film ki c LOS film ma peya ki inge 24 h me keto i te lero me ceng 1. Gin ma ki keto iye ni nyutu cal pa gin ma ki temo ni. d X-ray diffraction patterns me control ki LOS films ma peya ki inge 24 h me nyutu. Cal me SEM me filim ma ki tiyo kwede me temo e ki filim f LOS ingee cawa 24 me nyutu ne. Lok ma ki nongo ki iye ki miyo i kit me karatac ma ki nongo ki iye.
Watimo jami ma ki lwongo ni scanning electron microscopy (SEM) me neno alokaloka ma tye i kom gin ma ki lwongo ni perovskite film inge cawa 24 me keto lero, ma ki nyutu i cal 3e,f. I filim ma ki temo, nyig cam madongo ki balo ki gi doko buru ma tiino, ma rwate ki kit ma gin ma ki lwongo ni δ-phase product FAPbI3 nen kwede (Fig. 3e). Pi filim me LOS, nyig perovskite ni tye maber (lanyut 3f). Adwogi ni moko ni rwenyo pa I kelo alokaloka ki i dul macol me doko dul ma yellow, kun PbC2O4 dwoko piny macol, ma gengo rweny pa I. Kit ma rwom me vacancy i kom ngom tye malo loyo i kom nyig cam,34 dul man twero time i kom nyig cam. i kare acel ma gonyo iodine ki yubu VI. Kit ma ki waco kwede ki DFT, LOS twero gengo dongo pa VI ki gengo cito pa I ions i kom perovskite.
Medo ikom meno, adwogi pa dul ma ki lwongo ni PbC2O4 i kom teko pa pii ma ki lwongo ni perovskite films i yamo ma tye i yamo (rwom ma rwate ki 30-60%) ki kwano. Kit ma ki nyutu kwede i cal ma ki medo 9, LOS perovskite onwongo pud tye macol ingee nino 12, ma nongo gin ma ki lwongo ni control film ni oloko yellow. I rwom me XRD, gin ma ki lwongo ni control film ni nyutu rwom ma malo i 11.8° ma rwate ki δ phase pa FAPbI3, kun LOS perovskite tye ka gwoko black α phase maber (Supplementary Figure 10).
Steady-state photoluminescence (PL) ki time-resolved photoluminescence (TRPL) ki otiiyo kwede me kwedo adwogi pa lead oxalate i kom perovskite. I cal. cal 4a nyutu ni gin ma ki lwongo ni LOS ni omedo teko pa PL. I cal me PL, teko pa LOS film i kom kabedo weny ma tye 10 × 10 μm2 tye malo loyo pa control film (Supplementary Figure 11), ma nyutu ni PbC2O4 rwate ki perovskite film. Kare me kwo pa gin ma ki cwalo ni ki nongo ki i rwom me rweny pa TRPL ki gin acel ma ki lwongo ni exponential function (Fig. 4b). Kare me kwo pa gin ma ki lwongo ni LOS film ni tye 5.2 μs, ma bor loyo gin ma ki lwongo ni control film ma tye ki kare me kwo pa gin ma ki lwongo ni 0.9 μs, ma nyutu ni dwoko piny rwom me tic pa jami ma ki lwongo ni nonradiative recombination.
PL ma rwate ki b-spectra pa PL ma rii pi kare manok pa perovskite films i kom jami ma ki yubu ki gilaci. c SP curve pa gin ni (FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au). d EQE spectrum ki Jsc EQE spectrum ma ki keto kacel ki jami ma tiyo maber loyo. d Kit ma ler ma ki lwongo ni perovskite device ni cung kwede i kom cal ma ki lwongo ni Voc diagram. f MKRC ma ki tiyo kwede ki ITO/PEDOT:PSS/perovskite/PCBM/Au clean hole device. VTFL tye teko ma malo loyo me pongo trap. Ki ikom ngec eni wa kwano pek pa jami ma ki mako (Nt). Lok ma ki nongo ki iye ki miyo i kit me karatac ma ki nongo ki iye.
Me kwedo adwogi pa dul ma ki lwongo ni lead oxalate i kom tic pa jami ni, ki tiyo ki yoo macon me FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au. Wa tiyo ki formamidine chloride (FACl) ma calo gin ma ki medo i kom perovskite precursor ma ka methylamine hydrochloride (MACl) me nongo tic maber, pien FACl twero miiyo rwom me crystal maber ki gengo band gap pa FAPbI335 (nen Supplementary Figures 1 ki 2 pi poro ne matut). ). 12-14). IPA ki yero me bedo gin ma gengo pii pien en miiyo rwom maber ki rwom ma opore i perovskite films ka kiporo ki diethyl ether (DE) onyo chlorobenzene (CB)36 (Cal ma ki medo 15 ki 16). Pek pa PbC2O4 ki yubu maber me rwate maber ki rwom me tic pa oxalic acid (Cal ma ki medo 17). Cal ma ki kwanyo ki i dul ma ki lwongo ni SEM ma ki yubu maber ki jami ma ki lwongo ni LOS ki nyutu i cal me medo 18. Kit ma rwom me teko (CD) pi jami ma ki tiyo kwede ki LOS ki nyutu i cal 4c, ki jami ma ki kwanyo ki nyutu i Supplementary Table 3. Maximum power conversion efficiency (PCE) cells controls (34%, 24%, 24% J.C.). 25.75 mA cm-2 (25.74 mA cm-2), Voc 1.16 V (1.16 V) ki neno anyim (me anyim). Gin ma ki lwongo ni fill factor (FF) tye 78.40% (76.69%). PCE LOS PSC ma malo loyo tye 25.39% (24.79%), Jsc tye 25.77 mA cm-2, Voc tye 1.18 V, FF tye 83.50% (81.52%) ki i anyim (Scan me anyim). Gin ma ki lwongo ni LOS device ni onongo tic maber ma ki moko me 24.92% i ot yat ma ki geno pa ngat mukene ma tiyo ki mac (Cal ma ki medo 19). Kit ma jami ma ki lwongo ni external quantum efficiency (EQE) omiyo Jsc ma tye 24.90 mA cm-2 (control) ki 25.18 mA cm-2 (LOS PSC), kit meno, ma onongo tye maber ki Jsc ma kipimo i standard AM 1.5 G spectrum (Fig. .4d). ) . Kit ma ki poko kwede PCEs ma ki pimo pi control ki LOS PSCs ki nyutu i cal ma ki medo 20.
Kit ma ki nyutu kwede i cal 4e, wat ma tye i kin Voc ki teko pa lero ki kwano me kwedo adwogi pa PbC2O4 i kom rwate pa jami ma ki mako. Kit ma ki keto kwede line ma ki keto pi gin ma ki lwongo ni LOS tye 1.16 kBT/sq, ma tye piny loyo kit ma ki keto kwede line ma ki keto pi gin ma ki lwongo ni control device (1.31 kBT/sq), ma moko ni LOS ber me gengo rwate pa jami ma ki lwongo ni decoys. Wa tiyo ki diro me space charge current limiting (SCLC) me pimo pek pa gin ma ki lwongo ni perovskite film kun wa pimo dark IV ma tye i hole device (ITO/PEDOT:PSS/perovskite/spiro-OMeTAD/Au) kit ma ki nyutu kwede i cal ni. 4f Nyut. Pek pa trap ni ki kwano ki formula Nt = 2ε0εVTFL/eL2, kan ma ε tye dielectric constant pa perovskite film, ε0 tye dielectric constant pa vacuum, VTFL tye limiting voltage me pongo trap, e tye charge, L tye thickness pa perovskite film (6 nom). Pek pa gin ma ki lwongo ni VOC device ni ki kwano ni tye 1.450 × 1015 cm–3, ma tye piny loyo pek pa gin ma ki lwongo ni control device, ma tye 1.795 × 1015 cm–3.
Gin ma ki keto i bok ni ki temo i rwom me teko ma malo (MPP) i te lero me ceng i te nitrogen me neno kit ma en tiyo kwede pi kare malac (lanyut 5a). Iyonge cawa 550, gin ma ki lwongo ni LOS pud tye ka gwoko 92% me tic ne maber loyo, kun gin ma ki tiyo kwede me doro tic ni opoto piny nio wa i 60% me tic ne macon. Poko pa jami ma tye i jami macon ni ki pimo ki time-of-flight secondary ion mass spectrometry (ToF-SIMS) (Fig. 5b, c). Pol pa iodine ma ki nongo i kom ma malo ma ki gwoko iye jabu. Kit me gwoko yamo ma pe tiyo pe kwako jami ma balo kwo pa dano calo yamo ki yamo, ma nyutu ni jami ma tye iye (ma calo, ngwec pa ion) aye tye ka kelo peko. Malube ki adwogi pa ToF-SIMS, I- ki AuI2- ions kinongo gi i Au electrode, ma nyutu nya pa I ki i perovskite me donyo i Au. Teko pa lanyut pa I- ki AuI2- ion ma tye i jami ma ki tiyo kwede ni tye ma malo tyen 10 ma kato pa VOC ma ki nyutu ni. Ripot mukato angec onyutu ni ion permeation twero kelo dwoko piny oyotoyot i hole conductivity pa spiro-OMeTAD ki chemical corrosion me layer me electrode ma malo, ma weko rwate i kin jami ma tye i kin jami ni balo piny37,38. Ki kwanyo Au electrode ki ki kwanyo spiro-OMeTAD layer ki i kom gin ma ki keto iye ki pii ma ki lwongo ni chlorobenzene. Wan dong wa poko gin ma ki nyutu ni kun wa tiyo ki grazing incidente X-ray diffraction (GIXRD) (lanyut 5d). Adwogi ni nyutu ni gin ma ki lwongo ni control film ni tye ki diffraction peak ma nen maber i 11.8°, ma pe tye diffraction peak manyen ma nen i LOS sample. Adwogi ni nyutu ni rweny pa I ions madwong i kom gin ma ki lwongo ni control film ni kelo dongo pa δ phase, kun i LOS film ni yub man ki gengo ne.
Cawa 575 me lubo kor MPP ma pe ki umu i kom gin ma ki umu i yamo ma ki lwongo ni nitrogen ki lero ceng 1 labongo UV filter. ToF-SIMS poko pa b I- ki c AuI2- ions i LOS MPP control device ki aging device. Kala ma yellow, green ki orange rwate ki Au, Spiro-OMeTAD ki perovskite. d GIXRD pa perovskite film inge temo MPP. Lok ma ki nongo ki iye ki miyo i kit me karatac ma ki nongo ki iye.
Ki pimo rwom me lyeto ma cung i kom lyeto me moko ni PbC2O4 twero gengo cito pa ion (lanyut me medo 21). Teko me tic (Ea) me ion migration ki nongo ki pimo alokaloka i conductivity (σ) pa FAPbI3 film i rwom me lyeto ma pat pat (T) ki tic ki Nernst-Einstein relation: σT = σ0exp(−Ea/kBT), ma σ0 tye gin ma pe loko, kB tye gin ma pe loko. Wa nongo wel pa Ea ki i rwom me ln(σT) ma ki poro ki 1/T, ma tye 0.283 eV pi gin ma ki tiyo kwede ki 0.419 eV pi gin ma ki lwongo ni LOS device.
I agiki ne, wa miyo yoo me ngeyo yoo me balo pa FAPbI3 perovskite ki adwogi pa peko ma pat pat i kom teko ma gengo α-δ phase transition. I kin peko eni, peko me VI ki byeko ni twero kelo alokaloka ki i α me doko δ. Gin ma pe romo gonyo i pii ki ma rwate ki jami ma ki lwongo ni PbC2O4 ki keto me gwoko α-phase pa FAPbI3 kun gengo yubu I vacancies ki migration pa I ions. Yoo me tic man dwoko piny rwom me tic pa jami ma pe kelo mac, medo tic pa solar cell nio wa i 25.39%, ki medo rwom me tic. Adwogi wa ni miyo yoo me nongo formamidine PSCs maber ki ma cung matek kun gengo alokaloka ma okelo α me δ.
Titanium(IV) isopropoxide (TTIP, 99.999%) ki wilo ki bot Sigma-Aldrich. Hydrochloric acid (HCl, 35.0–37.0%) ki ethanol (anhydrous) ki wilo ki bot Guangzhou Chemical Industry. SnO2 (15 wt% tin(IV) oxide colloidal dispersion) ki wilo ki bot Alfa Aesar. Lead(II) iodide (PbI2, 99.99%) ki wilo ki bot TCI Shanghai (China). 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)-spirofluore,9′ (Spiro-OMeTAD, ≥99.5%), lithium bis(trifluoromethane)sulfonylimide (Li-TFSI, 99.95%), 4-tert -butylpyridine (tBP, 96%) ki wilo ki bot Xi'an Polymer Light Technology Company (China). N,N-dimethylformamide (DMF, 99.8%), dimethyl sulfoxide (DMSO, 99.9%), isopropyl alcohol (IPA, 99.8%), chlorobenzene (CB, 99.8%), acetonitrile (ACN). Ki wilo ki bot Sigma-Aldrich. Oxalic acid (H2C2O4, 99.9%) ki wilo ki bot Macklin. Jami weny ma ki tiyo kwede ni ki tiyo kwede kit ma ki nongo kwede labongo loko gin mo keken.
ITO onyo FTO substrates (1.5 × 1.5 cm2) ki lwoko ki detergent, acetone, ki ethanol pi dakika 10, kit meno, ki dong ki juku ne i te pii ma ki lwongo ni nitrogen. Gin ma ki lwongo ni TiO2 ma ki keto i kom gin ma ki lwongo ni FTO kun kitiyo ki pii ma ki lwongo ni titanium diisopropoxybis(acetylacetonate) i ethanol (1/25, v/v) ma ki keto i 500 °C pi dakika 60. Gin ma ki lwongo ni SnO2 colloidal dispersion ni ki keto i pii ma ki kwanyo iye ion i rwom me 1:5. I kom gin ma ki keto iye UV ozone pi dakika 20, ki keto gin ma ki lwongo ni SnO2 nanoparticles i 4000 rpm pi ceken 30 ki dong ki lyeto i 150 °C pi dakika 30. Pi gin ma ki lwongo ni perovskite precursor solution, 275.2 mg FAI, 737.6 mg PbI2 ki FACl (20 mol%) ki onyo gi i DMF/DMSO (15/1) mixed solvent. Gin ma ki lwongo ni perovskite layer ni ki yubu kun ki keto 40 μL me perovskite precursor solution i kom UV-ozone-treated SnO2 layer i 5000 rpm i yamo ma tye i kin piny pi 25 s. 5 ceken inge kare me agiki, 50 μL me MACl IPA solution (4 mg/mL) ki bolo oyoto i kom gin ma ki keto iye calo gin ma gengo buru. I ngeye, gin ma ki yubu manyen ni ki keto i 150°C pi dakika 20 ki dong i 100°C pi dakika 10. Iyonge juku gin ma ki lwongo ni perovskite nio wa i rwom me lyeto me ot, H2C2O4 solution (1, 2, 4 mg ma ki keto i 1 mL IPA) ki keto i 4000 rpm pi 30 s me juku perovskite ni. Gin ma ki lwongo ni spiro-OMeTAD ma ki yubu ki rubu 72.3 mg spiro-OMeTAD, 1 ml CB, 27 μl tBP ki 17.5 μl Li-TFSI (520 mg i 1 ml acetonitrile) ki keto i kom gin ni i 4000 rpm i kin 33 s. Me agiki ne, 100 nm ma pek pa Au layer ki odonyo i vacuum i rwom me 0.05 nm/s (0~1 nm), 0.1 nm/s (2~15 nm) ki 0.5 nm/s (16~100 nm) . ).
Tic pa SC pa perovskite solar cells ki pimo kun kitiyo ki Keithley 2400 mita ma tye i te solar simulator illumination (SS-X50) i rwom me mac ma romo 100 mW/cm2 ki ki moko kun kitiyo ki calibrated standard silicon solar cells. Ka pi ki waco mukene, SP curves ki pimo i glove box ma opong ki nitrogen i rwom me lyeto me ot (~25°C) i kit me neno anyim ki angec (voltage step 20 mV, delay time 10 ms). Gin ma ki lwongo ni shadow mask ni ki tiyo kwede me nongo kabedo ma tiyo maber ma romo 0.067 cm2 pi PSC ma ki pimo. Piim pa EQE ki otimo i yamo ma tye i kin piny kun kitiyo ki PVE300-IVT210 system (Industrial Vision Technology(s) Pte Ltd) ki mac ma ryeny ma ki keto i kom gin ni. Pi gwoko jami ni, temo jami ma ki lwongo ni non-encapsulated solar cells ki otimo i nitrogen glovebox i 100 mW/cm2 pressure labongo UV filter. ToF-SIMS ki pimo kun kitiyo ki PHI nanoTOFII time-of-flight SIMS. Ki nongo rwom me rwom ma malo kun kitiyo ki 4 kV Ar ion gun ki dit pa 400×400 μm.
Piim me X-ray photoelectron spectroscopy (XPS) kitimo i kom Thermo-VG Scientific system (ESCALAB 250) kun kitiyo ki monochromatized Al Kα (pi XPS mode) i rwom me 5.0 × 10–7 Pa. Scanning electron microscopy (SEM) kitimo i kom JESM-JOL-3030 F system. Kit ma kome nen kwede ki goro pa perovskite films ni ki pimo kun kitiyo ki atomic force microscopy (AFM) (Bruker Dimension FastScan). STEM ki HAADF-STEM ki gwoko gi i FEI Titan Themis STEM. UV-Vis absorption spectra ki pimo kun kitiyo ki UV-3600Plus (Shimadzu Corporation). Gin ma ki lwongo ni Space charge limiting current (SCLC) ki coyo i kom Keithley 2400 meter. Kit ma ler ma ki lwongo ni Steady-state photoluminescence (PL) ki time-resolved photoluminescence (TRPL) me kare me kwo pa carrier ki pimo kun ki tiyo ki FLS 1000 photoluminescence spectrometer. Cal ma ki nongo ki i PL ki pimo kun kitiyo ki Horiba LabRam Raman system HR Evolution. Fourier transform infrared spectroscopy (FTIR) ki otimo kun kitiyo ki Thermo-Fisher Nicolet NXR 9650 system.
I tic man, wa tiyo ki yoo me SSW me kwano yoo me loko rwom me α-phase me oo i δ-phase. I yoo me SSW, ngwec pa teko ma twero bedo i kom piny ki moko ki kit ma random soft mode (ma ki kwanyo me aryo), ma miyo kare me kwan matut ki ma rwate i kom teko ma twero bedo tye. I tic man, kwanyo yoo ki tiimo i kom 72-atom supercell, ki ma oo 100 initial/final state (IS/FS) pairs ki kwanyo gi i rwom me DFT. Malube ki IS/FS pairwise data set, yoo ma kubbe ki yub me acaki ki yub me agiki ki twero nongo ki rwate i kin atom, ki dong wot me yoo aryo i kom dul kom ma pat pat ki tiyo kwede me nongo yoo me loko. (VK-DESV). Iyonge yenyo kit ma jami tye ka loko kwede, yoo ma tye ki ariya ma piny loyo ki twero nongo ne ki keto ariya me teko.
Kwan me DFT weng ki tiimo kun kitiyo ki VASP (version 5.3.5), ma iye rwate pa electron-ion pa C, N, H, Pb, ki I atoms ki nyutu ki yub me amplified wave (PAW). Tic me rwate pa jami ma ki loko ni ki tito ki rwom me rwom ma malo i Perdue-Burke-Ernzerhoff parametrization. Ki keto teko ma ki keto pi yamo ma tye i wi yamo ni 400 eV. Gin ma ki lwongo ni Monkhorst-Pack k-point grid tye ki dit pa (2 × 2 × 1). Pi jami weny ma ki yubu, lattice ki atomic positions onwongo ki yubu maber nio ka rwom me peko ma malo onwongo tye piny 0.1 GPa ki rwom me teko ma malo onwongo tye piny 0.02 eV/Å. I kom ma ki nyutu, kom pa FAPbI3 tye ki dul 4, dul ma piny tye ki atom ma ocung ma rwate ki kom FAPbI3, ki dul adek ma malo twero wot agonya i kare me yubu ne. Dul ma ki lwongo ni PbC2O4 tye 1 ML ma pek ki tye i kom I-terminal pa FAPbI3, kan ma Pb tye ka rwate ki 1 I ki 4 O.
Pi ngec mukene ma mako kit ma ki yubu kwede kwan ni, nen karatac ma ki lwongo ni Natural Portfolio Report Abstract ma rwate ki pwony man.
Ngec weny ma kinongo onyo ki nyamo i kare me kwan man ki keto i pwony ma ki coyo, kacel ki ngec ma miiyo kony ki ngec ma ki coyo. Ngec ma ki nyutu i kwan man tye i https://doi.org/10.6084/m9.figshare.2410016440. Lok ma ki nongo ki iye ki miyo pi pwony man.
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