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Kugwisya tumpenda kwakabelesegwa loko kusumpula kubeleka kwamaselu aa lead triiodide perovskite solar cells, asi mpindu ya tumpenda tuindene-indene ku α-phase stability tiiyakazyibwa pe; Aawa, kubelesya njiisyo ya density functional theory, twakajana nzila yakusaanguna yakunyonyooka kwa formamidine lead triiodide perovskite kuzwa ku α-phase kuya ku δ-phase mpawo twiiya mbuzichita zintu zitali kabotu ku phase transition energy barrier. Zyakazwa mukukozyanisya zitondezya kuti busena butakwe iodine bulakonzya kuleta kunyonyooka nkaambo bulakonzya kucesya nguzu zyakukwabilila α-δ phase transition mpawo bulaa nguzu zyakupanga zili munsi kapati atala a perovskite. Kunjizya kwacibeela chiyumu cha lead oxalate iitakonzyi kunywika mumaanzi atala aa perovskite kulalesya kubola kwa α-phase, kulesya kweenda akuvwuuma kwa iodine. Kuyungizya waawo, nzila eeyi ilacesya kapati kusanganya zintu zitakwe mumuni mpawo ilayungizya kubeleka kabotu kwamaseelo aazuba kusika ku 25.39% (kuzumizigwa a 24.92%). Chibelesyo chitakwe nkomo chilakonzya kuzumanana kubeleka kabotu kwacho kwakusaanguna kusika ku 92% nikwakamana kubeleka anguzu zipati kwamahola aali 550 mumumuni wa 1.5 G.
Kusandula manguzu (PCE) kwamaselu aazuba aa perovskite (PSCs) kwasika aawo mpokugolela kusika ku 26%1. Kuzwa mu 2015, ma PSC aamazubaano ayanda formamidine triiodide perovskite (FAPbI3) mbuli chintu chikonzya kunjila mumumuni akaambo kakukkalilila kwacho kubotu loko mpawo akuba aandaano iili afwaafwi a Shockley-Keisser limit ya 2,3,4. Mupenzi, mafilimu aa FAPbI3 alainda mukusanduka kuzwa ku α phase iisiya kuya ku yellow non-perovskite δ phase aawo 5,6. Kuchitila kutabilila kupanga kwa delta phase, zintu zyiingi zikatazya kumvwisisisya zya perovskite zyakabambwa. Nzila iibelesyegwa kapati yakuzunda penzi eeli nkusanganya FAPbI3 antoomwe a methyl ammonium (MA+), cesium (Cs+) antoomwe a bromide (Br-) ions7,8,9. Nokuba boobo, ma perovskites aasanganizidwe alapenga akaambo kakuvwula kwa bandgap alimwi akwaandaana kwa phase akaambo ka photoinduced, calo cinyonganya mulimo alimwi akukkalikana kwa PSCs10,11,12.
Buvwuntauzi bwakachitika ino-ino bwakatondezya kuti FAPbI3 iijisi kkilisitali yomwe kakunyina kubelesya nzila eeyi ilakonzya kukkalwa moyo akaambo kakuti ilijisi tumpenda tusyoonto13,14. Aboobo, kucesya tumpenda kwiinda mukuyungizya bupati bwa FAPbI3 ninzila iiyandika kapati yakujana PSCs2,15 zibeleka obotu alimwi zitazungaani. Nokuba boobo, muchiindi chakubeleka kwa FAPbI3 PSC, kunyonyooka kuya kuchiimo cha yellow hexagonal non-perovskite δ chikonzya kuchitika16. Nchito eeyi kanjikanji italika aawo aali atalaa nyika alimwi amunyinza wamaila aakonzya kunjila mumaanzi, kupya alimwi amumuni akaambo kakujanika kwamasena manji aatali kabotu17. Aboobo, kugwisigwa kwaatala/maila kulayandika kuchitila kuti FAPbI318 ichite kabotu. Nzila zyiingi zyakugwisya tumpenda, kubikkilizya akutalisya ma perovskites aatakwe bupati, ma molecule aa acid-base Lewis, antoomwe amunyo wa ammonium halide, zyakachita kuyaambele kupati mu formamidine PSCs19,20,21,22. Kusikila sunu, ziiyo zyoonse zyabikkila maanu kumulimo wa tumpenda tuindene-indene mukuziba zintu zya optoelectronic mbuli kusanganya zintu zinyamuna, bulamfwu bwakumwaika antoomwe abupange bwazibeela zyama solar cells22,23,24. Mbuli chitondeezyo, njiisyo ya density functional theory (DFT) ilabelesyegwa kweezyeezya manguzu aakupanga antoomwe anguzu zyakujata zyamaleele aasiyene-siyene, eeyo iibelesyegwa kapati kusololela nzila yakuchita zintu zitali kabotu20,25,26. Mbokuyaabuceya mweelwe wazintu zilubide, kukkalikana kwacibelesyo kulayaambele. Nokuba boobo, mu formamidine PSCs, nzila zyakusungwaazya tumpenda tuindene-indene mukukkalilila kwachiimo antoomwe abukkale bwamumuni zyeelede kuba zisiyene. Kweelana aluzibo ndotujisi, kumvwisisisya kwakusaanguna kwakuti tumpenda tulakonzya kuchincha biyeni kuzwa ku cubic kuya ku hexagonal (α-δ) amulimu wa surface passivation mukukkalwa kwa α-FAPbI3 perovskite kuchili kumvwisisisya kabotu pe.
Aawa, twayubununa nzila yakunyonyooka kwa FAPbI3 perovskite kuzwa ku α-phase iisiya kuya ku δ-phase iisiya alimwi akuyunga kwatumpenda tuindene-indene aanguzu zyakukwabilila α-to-δ-phase kwiinda mu DFT. I busena butakwe muntu, oobo bukonzya kuchitwa muchiindi chakupanga mafilimu akubelesya minchina, bulalangilwa kuti bulakonzya kutalisya α-δ phase transition. Aboobo, twakanjizya bbazu lya lead oxalate (PbC2O4) litanyonyooki mumaanzi alimwi litazungaani mumakemikalu atala aa FAPbI3 kwiinda mukubelesya nzila ya in situ. Busena bwa lead oxalate (LOS) bulalesya kupanga kwa I vacancies mpawo bulalesya kweenda kwa I ions aawo nobusungwaazigwa akupya, mumuni, amagesi. LOS iizwa muli njiyo ilacesya kapati kusanganya zintu zitakwe mumuni mpawo yasumpula FAPbI3 PSC kusika ku 25.39% (yakasinizyigwa kusika ku 24.92%). Chibelesyo cha LOS chitakwe mubbokesi chakabamba 92% yakubeleka kwacho kwakusaanguna nikwakamana kubeleka aanguzu zyaatala (MPP) kwamahola aayinda ku 550 aamuwo (AM) wa 1.5 G wa radiation.
Twakasaanguna kuchita myeelwe ya ab initio kuti tujane nzila yakubola ya FAPbI3 perovskite kuzwa ku α phase kuya ku δ phase. Kwiinda munzila yakusanduka kwazibeela, kwajanwa kuti kusanduka kuzwa ku kkona lyazibeela zyotatwe [PbI6] octahedron mu cubic α-phase ya FAPbI3 kuya kuli one-dimensional edge-sharing [PbI6] octahedron mu hexagonal δ-phase ya FAPbI3 kwazuzikizyigwa. kutyoka 9. Pb-I ilapanga chilongwe muchiimo chakusanguna (Int-1), mpawo nguzu zyakwe zyasika ku 0.62 eV/cell, mbuli mbokutondezyedwe muchifanikisyo 1a. Eelyo octahedron niyasandulwa munzila ya [0\(\bar{1}\)1], nketani mfwaafwi ya hexagonal ilatanta kuzwa ku 1×1 kusika ku 1×3, 1×4 mpawo kumamanino ilanjila mu δ phase. Mweelwe wanzila yoonse ngu (011)α//(001)δ + [100]α//[100]δ. Kuzwa kumufanikisyo wakwaabila manguzu, kulakonzya kujanwa kuti musule aakusanduka kwa δ phase ya FAPbI3 muzibeela zitobela, chisinkilizyo changuzu chili munsi kwiinda cha α phase transition, chaamba kuti phase transition ilafwambaana. Zilibonya, ntaamu yakusaanguna yakulela kusanduka kwachiimo nchintu chipati kuti katuyanda kulesya kubola kwa α-phase.
Nzila yakusanduka kwachiimo kuzwa kulumwensyi kuya kululyo – chiimo cha FAPbI3 chisiya (α-chiimo), kutaanguna kwa Pb-I bond cleavage (Int-1) mpawo Pb-I bond cleavage (Int-2, Int -3 a Int -4) antoomwe a yellow phase FAPbI3 (delta phase). b Zisinkilizyo zyanguzu ku α kuya ku δ kusanduka kwa FAPbI3 kweendelanya amapenzi aasiyene-siyene. Muzila uulaa madoti utondeezya nguzu zyakukwabilila kkilisitala (0.62 eV). c Nguzu zyakupanga tumpenda twakusaanguna atala aa lead perovskite. Ibbazu lya abscissa ninzila yakukwabilila nguzu zya α-δ phase transition, mpawo nzila ya ordinate ninguzu zyakupanga tumpenda. Zibeela zilembedwe mubala wa grey, yellow a green nzimusyobo I (EB nsyoonto-FE mpati), musyobo II (FE mpati) antoomwe amusyobo III (EB nsyoonto-FE nsyoonto), kweendelana. d Nguzu zyakupanga tumpenda VI a LOS ya FAPbI3 mukweendelezya. e I chisinkilizyo chakulongela kwa ion mukweendelezya a LOS ya FAPbI3. f – chitondeezyo chakweenda kwa I ions (zibeela zya orenji) antoomwe a gLOS FAPbI3 (mubala wadota, lead; violet (mubala wa orenji), iodine (mobile iodine)) mubweendelezi bwa gf (kulumwensyi: atala; kululyo: chibeela, brown); kaboni; bbuluu lisiya - nitrogen; mubala uusalala – muya mubotu; pinki uusalala pyu – haayidirojeni). Data yakusaanguna ilapegwa muchikozyano cha data yakusaanguna.
Mpawo twakavwuntauzya munzila iilondokede nsungwaazyo ya tumpenda twamukati (kubikkilizya a PbFA, IFA, PbI, antoomwe a IPb antisite occupancy; Pbi a Ii interstitial atoms; antoomwe a VI, VFA, antoomwe a VPb vacancies), eezyo zibonwa kuti nzintu zipati. eezyo zipa kuti atomu anguzu zinyonyooke zitondezyedwe muchifanikisyo 1b a Supplementary Table 1. Chakugambya, teensi tumpenda toonse tucheya nguzu zya α-δ phase transition (Chitondeezyo 1b). Tusyoma kuti tumpenda tuli anguzu zyakupanga zili munsi-munsi antoomwe a α-δ phase transition energy barriers zilabonwa kuti zilanyonganya kukkalwa kwa phase. Mbuli mbukwakaambwa musule, busena bujisi lead bulabonwa kuti bulagwasya ku formamidine PSC27. Aboobo, twabikkila maanu ku PbI2-terminated (100) atala muchiimo chizwide lead. Nguzu zyakupanga tumpenda twatumpenda twaatala tutondezyedwe muchifanikisyo 1c a Supplementary Table 1. Kweelana anguzu zyakukwabilila (EB) anguzu zyakusanduka kwachiimo (FE), tumpenda ootu twaandaanizyigwa mumisyobo yotatwe. Musyobo I (EB nsyoonto-FE mpati): Nikuba kuti IPb, VFA antoomwe a VPb zilacesya loko nguzu zyakusanduka kwachiimo, zilijisi nguzu zyakupanga zipati. Aboobo, tusyoma kuti tumpenda twamusyobo ooyu tulaampindu nsyoonto mukusanduka kwazibeela nkaambo tazichitiki pe. Musyobo wabili (EB mpati): Akaambo kakusumpuka kwanguzu zyakucinca kwa α-δ, tumpenda twa PbI, IFA antoomwe a PbFA tazinyonganyi kukkalwa kwa α-FAPbI3 perovskite. Musyobo wachitatu (EB muniini-FE muniini): VI, Ii a Pbi tumpenda tujisi manguzu masyoonto aakupanga tulakonzya kuleta kunyonyooka kwachiimo chisiya. Ikapati kakuli FE a EB VI zili munsi, tusyoma kuti nzila iibeleka kabotu nkucesya zyuuno zya I.
Kuchesya VI, twakabamba bbazu lya PbC2O4 kuti tusumpule busena bwa FAPbI3. Kweezyanisya a organic halide salt passivators zilimbuli phenylethylammonium iodide (PEAI) antoomwe a n-octylammonium iodide (OAI), PbC2O4, eeyo iitakwe ma ayoni aa halogen, iliimvwi nji, taikonzyi kunywika mumaanzi, mpawo ilakonzya kuzimaana kuti yasungwaazigwa. Kukkalilila kubotu kwabusi bwaatala anguzu zya magesi zya perovskite. Kunywika kwa PbC2O4 mumaanzi kuli buyo a 0.00065 g/L, ooko nkusyoonto kwiinda kwa PbSO428. Ichakatazyide loko, zibeela zya LOS ziyumu alimwi zyeelene zilakonzya kubambwa kabotu-kabotu kumafilimu aa perovskite kubelesya nzila zyakusanduka (langa munsi). Twakachita zikozyanyo zya DFT zyakujatana aakati ka FAPbI3 a PbC2O4 mbuli mbokutondezyedwe muchifanikisyo chakuyungizya 1. Chitondeezyo chakuyungizya 2 chitondeezya manguzu aakupanga tumpenda nikwakamana kubikkwa LOS. Twakajana kuti LOS taiyungizyi buyo manguzu aakupanga tumpenda twa VI a 0.69–1.53 eV (Chitondeezyo 1d), pesi alimwi ilayungizya manguzu aakubelesya I aabusena bwakulonga akuzwa (Chitondeezyo 1e). Muchibaka chakusanguna, ma ayoni aa I azwa mujulu lya perovskite, akusiya ma ayoni aa VI muchiimo cha lattice anguzu zya 0.61 eV. Musule akubikkwa kwa LOS, akaambo kakulesyegwa kwa steric, manguzu aakutalisya kweendeenda kwa I ions alatanta kusikila. 1.28 eV. Muchiindi chakulongela kwa I ions kuzwa atala a perovskite, nguzu zyakukwabilila mu VOC azyalo zilisumpukide kwiinda mumusamu wakulanga (Fig. 1e). Mifanikisyo ya I ion migration pathways mu control a LOS FAPbI3 itondezyedwe mu Cifwanikiso 1 f a g, kweendelana. Zyakazwa mukukozyanisya zitondezya kuti LOS ilakonzya kulesya kupanga tumpenda twa VI akuvwuuma kwa I, aboobo kulesya kucinca kwa α kuya ku δ.
Kuswaangana aakati ka oxalic acid a FAPbI3 perovskite kwakasunkwa. Nikwakamana kusanganya musamu wa oxalic acid a FAPbI3, mweelwe mupati wachintu chituba wakapangwa, mbuli mbokutondezyedwe muchifanikisyo chakuyungizya 2. Chitondeezyo chakajanwa kuti nchintu chisalala cha PbC2O4 kubelesya X-ray diffraction (XRD) (Cifwanikiso chakuyungizya 3) antoomwe a Fourier transform infrared spectroscopy (SIR) (Cifwanikiso chakuyungizya 4). Twakajana kuti oxalic acid ilakonzya kunywika kapati mu isopropyl alcohol (IPA) aawo mpokupya loko mpawo ilakonzya kunywika kusika ku 18 mg/mL, mbuli mbokutondezyedwe mu Supplementary Figure 5. Eezi zipa kuti kube kuuba nkaambo IPA, mbuli chintu chidumide, tachinyonganyi perovskite layer muchiindi chifwiifwi. Aboobo, kwiinda mukubikka filimu ya perovskite mumusamu wa oxalic acid naa kuvwumba musamu wa oxalic acid atalaa perovskite, PbC2O4 iiteteete alimwi iiyumu ilakonzya kujanwa akufwambaana atalaa filimu ya perovskite kweendelanya anzila eeyi: H2C2O4 + FAPI3 = PbI3 + FAIO4 FAI ilakonzya kunyoneka mu IPA mpawo ilagwisigwa muchiindi chakujika. Bupati bwa LOS bulakonzya kweendelezyegwa achiindi chakusanduka antoomwe akuvwula kwa precursor.
Zifwanikiso zya Scanning electron microscopy (SEM) zya control a LOS perovskite films zitondezyedwe muzifwanikiso 2a,b. Zyakazwa muzyaambilizyo zitondezya kuti bupange bwa perovskite bulikwabilidwe obotu, mpawo mweelwe mupati wazibeela zibotu zyabikkwa atala aamaila, alo ayelede kwiiminina PbC2O4 layer yakapangwa a in-situ reaction. Filimu ya LOS perovskite ilijisi busena buteteete mbichani (Chitondeezyo Chakuyungizya 6) antoomwe ambali mpati yakuguma maanzi kweelanisigwa afilimu yakweendelezya (Cifwanikiso Chakuyungizya 7). Inzila yakulanga zintu zyiingi loko (HR-TEM) yakabelesegwa kwaandaanya bbazu lyaatala lyachintu eecho. Mukweezyanisya afilimu yeendelezya (Mufanikisyo 2c), bbazu liteteete likozyenye alimwi liyumu lijisi bupati bwa 10 nm lilabonwa kabotu atala aa LOS perovskite (Mufanikisyo 2d). Kubelesya high-angle annular dark-field scanning electron microscopy (HAADF-STEM) kulanga-langa kujatana aakati ka PbC2O4 a FAPbI3, kujanika kwamasena aa FAPbI3 aamabwe aa PbC2O4 kulakonzya kubonwa antangalala (Supplementary Figure 8). Bupange bwaatala bwa perovskite nikwakamana kusilikwa a oxalic acid bwakazyibwa kwiinda mukupima kwa X-ray photoelectron spectroscopy (XPS), mbuli mbokutondezyedwe muzifwanikiso 2e-g. Muchifanikisyo 2e, C 1s zili afwaafwi a 284.8 eV antoomwe a 288.5 eV zili muzitondezyo zya CC antoomwe a FA, kweendelana. Mukweezyanisya a membrane yeendelezya, membrane ya LOS yakatondeezya aayungizyidwe a 289.2 eV, yakazwa ku C2O42-. O 1s spectrum ya LOS perovskite itondezya O 1s zyotatwe ziindene a 531.7 eV, 532.5 eV, antoomwe a 533.4 eV, zyeendelana a deprotonated COO, C=O ya intact oxalate groups 30 antoomwe a O atoms ya OH component (Fig. 2). )). Kuchikozyano chakweendelezya, kwakabonwa biyo O 1s nsyoonto, eeyo iikonzya kwaambwa kuti yakazwa mu oxygen yakazwa atala. Bube bwa membrane yeendelezya ya Pb 4f7/2 antoomwe a Pb 4f5/2 zili a 138.4 eV antoomwe a 143.3 eV, kweendelana. Twakabona kuti LOS perovskite itondezya kucinca kwa Pb peak ya 0.15 eV kuya ku nguzu zyakujata zisumpukide, kutondezya kuswaangana kupati aakati ka C2O42- a Pb atoms (Fig. 2g).
a SEM zifwanikiso zyakweendelezya a b LOS perovskite mafilimu, atala. c High-resolution cross-sectional transmission electron microscopy (HR-TEM) of control and d LOS perovskite films. XPS iisumpukide ya e C 1s, f O 1s antoomwe a g Pb 4f mafilimu aa perovskite. Data yakusaanguna ilapegwa muchikozyano cha data yakusaanguna.
Kweelana a DFT zyazwa, kwakaambwa kuti VI defects a I migration zilakonzya kupa kuti kube kusanduka kuzwa ku α kuya ku δ. Malipooti aakaindi atondezya kuti I2 ilafwambaana kuzwa mumafilimu aa PC-based perovskite muchiindi chakubikkwa mumuni nikwakamana kubikkwa mafilimu mumumuni akupya31,32,33. Kusinizya mulimo wa lead oxalate ku α-phase ya perovskite, twakabikka mafilimu aa control alimwi a LOS perovskite mumabbodela aagilazi aasalala aajisi toluene, kweendelana, mpoonya twakaabikka mumuni wazuba omwe kwamawoola aali 24. Twakapima kunjila kwamumuni uuzwa mumulengalenga (UV-Vis). ) musamu wa toluene, mbuli mbokutondezyedwe muchifanikisyo 3a. Mukweezyanisya aachikozyano chakweendelezya, nguzu zya I2 zyakali munsi kapati zyakabonwa muchiimo cha LOS-perovskite, kutondezya kuti LOS iijisi nguzu ilakonzya kulesya kuzwa kwa I2 kuzwa mufilimu ya perovskite muchiindi chakubbizigwa mumumuni. Zifwoto zyamafilimu aa LOS perovskite zitondezyedwe mukati kazifwanikiso 3b a c. I LOS perovskite ichilisiya, mpawo bunji bwa filimu yeendelezya yakasanduka kuba yellow. I UV-kuboneka kwakunjila kwa filimu iibikkidwe mumaanzi itondezyedwe mumifanikisyo. 3b, c. Twakabona kuti kuyoya kweendelana a α mufilimu yakweendelezya kwakaceya. Kupima kwa X-ray kwakachitwa kuchitila kulemba kusanduka kwabupange bwamakristalu. Nikwakainda mawoola aali makumi obilwe atune (24) mumuni, perovskite yakatondeezya chitondezyo cha δ-phase chiyumu (11.8°), mpawo LOS perovskite yakachili kubamba mubala muubauba (Chitondeezyo 3d).
Kuboneka kwa UV kwa toluene solutions oomo filimu yakweendelezya a LOS filimu mozyakali kubbizigwa munsi lyamumuni wazuba lyomwe kwamahola aali makumi obilwe atune. Chitondeezyo chitondeezya nkapu oomo filimu imwi aimwi moyakabikkwa mubunji bweelene bwa toluene. b UV-Vis absorption spectra ya control film a c LOS film kakutanaba akumana 24 h yakubbizyigwa munsi lyamumuni wazuba lyomwe. Mukati utondeezya mufanikisyo wafilimu yakusunka. d X-ray diffraction patterns of control and LOS films kakutanaba a 24 h yakuzwa. Zifwanikiso zya SEM zya filimu e a filimu f LOS musule aamawoola aali makumi obilwe atune aakutondezyegwa. Data yakusaanguna ilapegwa muchikozyano cha data yakusaanguna.
Twakachita kupima kwa scanning electron microscopy (SEM) kuti tubone kuchincha kwabupange bwa perovskite filimu nikwakainda mawoola aali makumi obilwe atune kamumuni, mbuli mbokutondezyedwe muzifwanikiso 3e,f. Mufilimu yakulanganya, maila mapati akanyonyoonwa akusanduka kuba tunsingo tusyoonto, ooto twakali kweendelana abupange bwa δ-phase product FAPbI3 (Fig. 3e). Kumafilimu aa LOS, maila aa perovskite akkala kabotu (Chitondeezyo 3f). Izyazwa zyakasinizya kuti kusweekelwa kwa I kupa kuti kube kusanduka kuzwa kuchiimo chisiya kuya kuchiimo chisalala pyu, mpawo PbC2O4 ilakkazyika chiimo chisiya, akulesya kusweekelwa kwa I. Mbwaanga busena butakwe chintu atala mbupati kwiinda bupati bwamaila,34 eechi chiimo chilalangilwa kuchitika atala aamaila. aawo aawo kugwisya iodine akupanga VI. Mbuli mbukwakasinsimwa a DFT, LOS ilakonzya kulesya kupanga tumpenda twa VI akulesya kweenda kwa I ions kuya ku perovskite surface.
Kuyungizya waawo, mulimo wa PbC2O4 layer kukukazya kuteta kwamafilimu aa perovskite mumuwo (kutontola kwa 30-60%) wakavwuntauzyigwa. Mbuli mbokutondezyedwe muchifanikisyo chakuyungizya 9, LOS perovskite yakachili isiya musule lyamazuba ali kkumi aabili, mpawo filimu yakulanganya yakasanduka kuba yellow. Mukupima kwa XRD, filimu yeendelezya itondezya nsumbu mpati a 11.8° kweendelana a δ phase ya FAPbI3, mpawo LOS perovskite ilabamba kabotu α phase iisiya (Supplementary Figure 10).
Mumuni uutazungaani (PL) antoomwe amumuni uuzwa muchiindi (TRPL) zyakabelesegwa kwiiya mulimo wa lead oxalate atala aa perovskite. Muchikozyano. Chikozyano 4a chitondezya kuti filimu ya LOS yakayungizya nguzu zya PL. Muchifanikisyo cha PL, nguzu zya filimu ya LOS mubusena boonse bwa 10 × 10 μm2 zilisumpukide kwiinda filimu ya control (Chitondeezyo chakuyungizya 11), kutondezya kuti PbC2O4 ilalesya filimu ya perovskite. Buumi bwasikunyamuna bujanwa kwiinda mukweezyanisya kubola kwa TRPL amulimo omwe wakuyungizya (Mufanikisyo. 4b). Buumi bwakunyamuna bwafilimu ya LOS mbu 5.2 μs, oobo bulamfwu kwiinda filimu yakweendelezya iijisi buumi bwakunyamuna bwa 0.9 μs, kutondezya kucheya kwakusanganya kutali kwamumuni.
PL iitazungaani antoomwe a b-spectra ya PL yachiindi chifwiifwi yamafilimu aa perovskite aagilazi. c SP curve yachibelesyo (FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au). d EQE spectrum antoomwe a Jsc EQE spectrum zyakaswaanganizyigwa kuzwa kuchibelesyo chibeleka obotu. d Kusyoma kwanguzu zyamumuni wachibelesyo cha perovskite achifanikisyo cha Voc. f Kuvwuntauzya kwa MKRC kubelesya ITO/PEDOT:PSS/perovskite/PCBM/Au chintu chakusanzya mpako. VTFL ninzila mpati yakuzuzya magesi. Kuzwa ku data eeyi twakabala bupati bwakujata (Nt). Data yakusaanguna ilapegwa muchikozyano cha data yakusaanguna.
Kuvwuntauzya mulimo wa lead oxalate layer kukubeleka kwa chintu, FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au contact structure yakabelesegwa. Tubelesya formamidine chloride (FACl) mbuli chintu chiyungizyidwe ku perovskite precursor muciindi ca methylamine hydrochloride (MACl) kuchitila kuti chibelesyo chibeleke kabotu, nkaambo FACl ilakonzya kupa bubotu bwama crystal akutantamuka band gap ya FAPbI335 (Langa Supplementary Figures 1 a 2 kuti ukonzye kweezyanisya kabotu). ). 12-14). IPA yakasalwa kuti ibe chintu chikwabilila nkaambo ilapa bubotu bwamakristalu mpawo ilaampindu mbotu mumafilimu aa perovskite kweelanisigwa a diethyl ether (DE) naa chlorobenzene (CB)36 (Zifwanikiso Zyakuyungizya 15 a 16). Bulemu bwa PbC2O4 bwakabambululwa kabotu-kabotu kuti bukonzye kweendelanya kabotu kugwisya tumpenda akutola magesi kwiinda mukuchincha bunji bwa oxalic acid (Chitondeezyo Chakuyungizya 17). Zifwanikiso zya SEM zyaatala azibelesyo zya LOS zitondezyedwe mu Supplementary Figure 18. Zibeela zya current density (CD) zya control a LOS devices zitondezyedwe mu 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) antoomwe akujokela musule (kuya kunembo) scan. Ikuzuzya (FF) nku 78.40% (76.69%). PCE LOS PSC mpati 25.39% (24.79%), Jsc 25.77 mA cm-2, Voc 1.18 V, FF 83.50% (81.52%) kuzwa musule (Scan kuya kunembo). Chibelesyo cha LOS chakazwidilila kuchita obotu kwa 24.92% mu laboratory yamumuni iisyomwa (Supplementary Figure 19). Ikubeleka kabotu kwaanze (EQE) kwakapa Jsc iiswaangene ya 24.90 mA cm-2 (kweendelezya) a 25.18 mA cm-2 (LOS PSC), kweendelana, eeyo yakali kweendelana a Jsc yakapimwa mu AM 1.5 G spectrum (Fig. .4d). ) . Kwaabila kwamweelwe wa PCEs zyakapimwa zya control a LOS PSCs zitondezyedwe mu Supplementary Figure 20.
Mbuli mbokutondezyedwe muchifanikisyo 4e, kujatana aakati ka Voc anguzu zyamumuni kwakabalilwa kuti kuvwuntauzyigwe mulimo wa PbC2O4 mukuswaanganya busena bugwasyilizyigwa akukwabilila. Kuseluka kwamuzila uubikkidwe wachibelesyo cha LOS ngu 1.16 kBT/sq, ooko nkucheya kwamuzila uubikkidwe wachibelesyo cheendelezya (1.31 kBT/sq), kusinizya kuti LOS ilagwasya mukulesya kuswaangana kwaatala aama decoys. Tubelesya nzila ya space charge current limiting (SCLC) kuti tupimye bunji bwakubula nguzu kwa filimu ya perovskite kwiinda mukupima bube bwa dark IV bwa hole device (ITO/PEDOT:PSS/perovskite/spiro-OMeTAD/Au) mbuli mbokutondezyedwe achifanikisyo. 4f Tondezya. Bunji bwachiteyo bubalilwa a fomula Nt = 2ε0εVTFL/eL2, aawo ε mpoili dielectric constant ya filimu ya perovskite, ε0 nji dielectric constant ya vacuum, VTFL nji voltage iilesyela kuzuzya kkaadi, e nji nguzu, L nji bupati bwa perovskite film (6 nm). Bupati bwakulezya bwachibelesyo cha VOC bwabalilwa kuti buli 1.450 × 1015 cm–3, oobo buli munsi abulemu bwakulezya bwachibelesyo chakweendelezya, oobo buli 1.795 × 1015 cm–3.
Chibelesyo eechi chitakwe mabbokesi chakasunkwa aanguzu zyaatala (MPP) mumumuni wazuba woonse munsi lya nitrogen kuti chibone naa chibeleka kwacho kwachiindi chilamfu (Chitondeezyo 5a). Nikwakainda mahola aali 550, LOS chakachili kubamba 92% yakubeleka kwacho, mpawo chibelesyo chakweendelezya chakaseluka kusika ku 60% yakubeleka kwacho kumatalikilo. Kwaabila kwazintu muchibelesyo chakaindi kwakapimwa achiindi-chakuuluka cha secondary ion mass spectrometry (ToF-SIMS) (Fig. 5b, c). Kuyoboloka kupati kwa iodine kulakonzya kubonwa mubusena bwangolida bwaatala. Ziimo zyakukwabilila muya uutakwe nguzu tazibikkilizyi zintu zikonzya kunyonganya busena mbuli buteteete amuuya, kutondeezya kuti nzila zyamukati (nkokuti, kweendeenda kwa ion) nzizyo zipa kuti kube boobo. Kweelana a ToF-SIMS zyakajanwa, I- antoomwe a AuI2- ions zyakajanwa mu Au electrode, kutondezya kumwaika kwa I kuzwa ku perovskite kuya ku Au. Inguzu zya I- antoomwe a AuI2- ions muchibelesyo chakweendelezya zili aafwaafwi ziindi zili kkumi kwiinda zya VOC. Malipooti aakaindi atondezya kuti kunjila kwa ion kulakonzya kuleta kucheya kwakufwambaana kwa spiro-OMeTAD akubola kwamakemikalu kwa electrode yaatala, aboobo kunyonganya kujatana aakati kachibelesyo37,38. I electrode ya Au yakagwisigwa mpawo bbazu lya spiro-OMeTAD lyakasanzigwa kuzwa ansi aamusamu wa chlorobenzene. Mpawo twakabamba filimu eeyi kubelesya grazing incidence X-ray diffraction (GIXRD) (Chitondeezyo 5d). Zyakazwa muzyaambilizyo zitondezya kuti filimu yeendelezya ilijisi nsumbu iilibonya a 11.8°, kakuli taakwe nsumbu mpya ilibonya muchikozyano cha LOS. Zyakazwa muzyaambilizyo zitondezya kuti kusweekelwa kupati kwa I ions mufilimu yeendelezya kuleta kuzyalwa kwa δ phase, mpawo mufilimu ya LOS eeyi nzila ilalesyegwa.
mawoola aali 575 aakutobelezya MPP kuzumanana kwachibelesyo chitajalidwe mumulengalenga wa nitrogen antoomwe amumuni wazuba lyomwe kakunyina sefa ya UV. ToF-SIMS kwaabwa kwa b I- antoomwe a c AuI2- ions mu LOS MPP control device a aging device. Mibala ya yellow, green a orenji yeendelana a Au, Spiro-OMeTAD antoomwe a perovskite. d GIXRD ya filimu ya perovskite nikwakamana kusunkwa kwa MPP. Data yakusaanguna ilapegwa muchikozyano cha data yakusaanguna.
Kuyungizya kweendelana akupya kwakapimwa kusinizya kuti PbC2O4 ilakonzya kulesya kweenda kwa ion (Chitondeezyo Chakuyungizya 21). Nguzu zyakutalisya (Ea) zyakulongela kwa ion zilajanwa kwiinda mukupima kuchincha kwakutola (σ) kwa filimu ya FAPbI3 kuma temperature aasiyene (T) akubelesya nzila ya Nernst-Einstein: σT = σ0exp(−Ea/kBT), aawo σ0 nkwiinda, kB nkoili Boltzman. Tujana mpindu ya Ea kuzwa kukuseluka kwa ln(σT) kweelanisigwa a 1/T, ooko kuli 0.283 eV kuchibelesyo cheendelezya a 0.419 eV kuchibelesyo cha LOS.
Muchi chifwiifwi, twapa nzila yakuziba nzila yakunyonyooka kwa FAPbI3 perovskite ansungwaazyo ya tumpenda tuindene-indene aatala anguzu zya α-δ phase transition. Akati kazeezi zilubide, zilubide zya VI zilalangilwa kuti zilakonzya kuleta kusanduka kuzwa ku α kuya ku δ. Ibbazu lya PbC2O4 litanyonyooki mumaanzi alimwi litazungaani mumakemikalu lyakanjizigwa kuti likwabilile α-phase ya FAPbI3 kwiinda mukulesya kupanga kwa I vacancies akulonga kwa I ions. Eeyi nzila ilacesya kapati kusanganya zintu zitakwe mumuni, ilayungizya bubotu bwa solar cell kusika ku 25.39%, mpawo ilasumpula kukkalikana kwakubeleka. Zyakajanwa kulindiswe zipa busolozi bwakujana formamidine PSCs zibeleka kabotu alimwi zitazungaani kwiinda mukulesya α kuya ku δ phase transition akaambo kakulezya.
Titanium(IV) isopropoxide (TTIP, 99.999%) yakaulwa kuzwa ku Sigma-Aldrich. Hydrochloric acid (HCl, 35.0–37.0%) antoomwe a ethanol (anhydrous) zyakaulwa kuzwa ku Guangzhou Chemical Industry. SnO2 (15 wt% tin(IV) oxide colloidal dispersion) yakaulwa kuzwa kuli Alfa Aesar. Lead(II) iodide (PbI2, 99.99%) yakaulwa kuzwa ku 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)-9′-spirofluore (Spiro-OMeTAD, ≥99.5%), lithium bis(trifluoromethane)sulfonylimide (Li-TFSI, 99.95%), 4-tert -butylpyridine (tBP, 96%) yakaulwa kuzwa ku 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). Zyakaulwa kuzwa kuli Sigma-Aldrich. Oxalic acid (H2C2O4, 99.9%) yakaulwa kuzwa kuli Macklin. Makemikalu woonse akabelesegwa mbuli mbwaakatambulwa kakunyina kuchincha kuli koonse.
ITO naa FTO (1.5 × 1.5 cm2) zyakasanzigwa a detergent, acetone, a ethanol kwamaminiti aali kkumi, mpawo zyakayuminizyigwa a nitrogen. Chikwabilizyo cha TiO2 chakabikkwa a FTO kubelesya musamu wa titanium diisopropoxybis(acetylacetonate) mu ethanol (1/25, v/v) wakabikkwa a 500 °C kwamaminiti aali 60. I SnO2 colloidal dispersion yakasanzyigwa amaanzi aatakwe ion mumweelwe wa 1:5. Aawo aasalala aakabikkwa a UV ozone kwamaminiti aali makumi abili, filimu nsyoonto ya SnO2 nanoparticles yakabikkwa a 4000 rpm kwamasekondi aali 30 mpawo yakapya a 150 °C kwamaminiti aali 30. Ku perovskite precursor solution, 275.2 mg FAI, 737.6 mg PbI2 antoomwe a FACl (20 mol%) zyakanyonyoonwa mu DMF/DMSO (15/1) mixed solvent. Ibbazu lya perovskite lyakabambilwa akusanzya 40 μL ya perovskite precursor solution atala lya UV-ozone-treated SnO2 layer a 5000 rpm mumuwo uuli afwaafwi kwa 25 s. 5 masekondi kuzwa muchiindi chamamanino, 50 μL ya MACl IPA solution (4 mg/mL) yakafwambaana kuwisigwa aansi mbuli chintu chikwabilila. Mpawo, mafilimu aakabambilwa akali kupya a 150°C kwamaminiti aali 20 mpawo a 100°C kwamaminiti aali 10. Nikwakamana kutontozya filimu ya perovskite kusikila kutempelecha yamukati, musamu wa H2C2O4 (1, 2, 4 mg wakanyonyooka mu 1 mL IPA) wakasanzyigwa a 4000 rpm kwamasekondi aali 30 kuchitila kuti perovskite itabelesyi pe. Musamu wa spiro-OMeTAD wakabambilwa akusanganya 72.3 mg spiro-OMeTAD, 1 ml CB, 27 μl tBP antoomwe a 17.5 μl Li-TFSI (520 mg mu 1 ml acetonitrile) wakabikkwa a filimu a 4000 rpm mukati ka 033 s. Kumamanino, 100 nm bbazu lya Au lyakazwa mumulengalenga amweelwe wa 0.05 nm/s (0~1 nm), 0.1 nm/s (2~15 nm) a 0.5 nm/s (16~100 nm) . ).
Ikubeleka kwa SC kwamaseelo aazuba aa perovskite kwakapimwa kubelesya Keithley 2400 mita munsi lyamumuni wazuba (SS-X50) amumuni uusimide wa 100 mW/cm2 mpawo kwakasinizyigwa kubelesya maseelo aazuba aa silicon aasalala. Kufumbwa kuti kwategwa bumbi, SP curves zyakali kupimwa mubbokesi lyamagilovu lyakazwide nitrogen aawo mpokupya (~25°C) munzila zyakulanga kunembo akujokela musule (voltage step 20 mV, delay time 10 ms). Chivwumbyo chamumuni chakabelesegwa kujana busena buli kabotu bwa 0.067 cm2 bwa PSC yakapimwa. Kupima kwa EQE kwakachitwa mumuya uuli afwaafwi kubelesya nzila ya PVE300-IVT210 (Industrial Vision Technology(s) Pte Ltd) mumuni uuzwa mumubala omwe uubikkilide maanu kuchibelesyo. Kuti chibelesyo chikkale kabotu, kusunka maseelo aazuba aatakwe mubbokesi kwakachitwa mubbokesi lyamagilovu lya nitrogen a 100 mW/cm2 kakunyina chisefa cha UV. ToF-SIMS ilapimwa kubelesya PHI nanoTOFII time-of-flight SIMS. Kuvwuntauzya kwakuya ansi kwakajanwa kubelesya 4 kV Ar ion gun abusena bwa 400×400 μm.
Kupima kwa X-ray photoelectron spectroscopy (XPS) kwakachitwa a Thermo-VG Scientific system (ESCALAB 250) kubelesya monochromatized Al Kα (ya XPS mode) a pressure ya 5.0 × 10–7 Pa. Scanning electron microscopy (SEM) yakachitwa a JESM-JOL-303F system. Bupange bwaatala abuyumuyumu bwamafilimu aa perovskite zyakali kupimwa kubelesya atomic force microscopy (AFM) (Bruker Dimension FastScan). STEM a HAADF-STEM zilachitilwa ku FEI Titan Themis STEM. Kunjila kwa UV-Vis kwakapimwa kubelesya UV-3600Plus (Shimadzu Corporation). Inguzu zyakulesya nguzu zyamulengalenga (SCLC) zyakalembwa a Keithley 2400 mita. Kumweka kwamumuni (PL) antoomwe akumweka kwamumuni kwachiindi (TRPL) kwakubola kwachiindi chilamfu kwakapimwa kubelesya FLS 1000 photoluminescence spectrometer. Zifwanikiso zya PL zyakapimwa kubelesya Horiba LabRam Raman system HR Evolution. Fourier transform infrared spectroscopy (FTIR) yakachitwa kubelesya Thermo-Fisher Nicolet NXR 9650 system.
Mumulimo ooyu, twabelesya nzila ya SSW yakusandula nzila yakucinca kuzwa ku α-phase kuya ku δ-phase. Munzila ya SSW, kweendeenda kwanguzu zikonzya kubelesegwa kulajanwa kwiinda mukulanga nzila ya random soft mode (second derivative), eeyo iipa kuti kube chiiyo chili kabotu-kabotu changuzu zikonzya kuchitika. Mumulimo ooyu, kusampulwa kwanzila kuchitwa aa 72-atomu supercell, mpawo zyiinda ku 100 zyakusaanguna/zyakumamanino (IS/FS) zyobile zyakayobolwa a DFT level. Kwiinda mu IS/FS pairwise data set, nzila iiswaanganya bupange bwakusaanguna abupange bwamamanino ilakonzya kuzyibwa kwiinda mukuzuminana aakati kama atomu, mpawo kweenda kwanzila zyobile kweendelana abwaanda bwachintu chikonzya kuchincha kubelesegwa kuzyiba nzila yakusanduka. (VK-DESV). Musule akuyandaula chiimo chakusanduka, nzila iijisi chisinkilizyo chili munsi ilakonzya kuzyibwa kwiinda mukubikka muzibeela zisinkilizyo zyanguzu.
Kubalila koonse kwa DFT kwakachitwa kubelesya VASP (version 5.3.5), ooko kuswaangana kwa electron-ion kwa C, N, H, Pb, antoomwe a I ma atomu kwakatondezyegwa a projected amplified wave (PAW) scheme. Mulimo wakucincanya upandululwa akweezyeezya kwakuvwuzyanya kwa Perdue-Burke-Ernzerhoff parametrization. Mugaano wanguzu zya mayuwe aandeke wakabikkwa a 400 eV. Monkhorst-Pack k-point grid ilijisi bupati bwa (2 × 2 × 1). Kuzintu zyoonse zyakabambwa, zibeela zya lattice a atomic zyakabambululwa kusikila chiindi chilamfu chakali munsi aa 0.1 GPa mpawo chibeela changuzu chipati chakali munsi a 0.02 eV/Å. Muchikozyano chaatala, atala lya FAPbI3 lijisi zibeela zyone, cibeela caansi chili ama atomu aatazungaani aakozyanisya mubili wa FAPbI3, mpawo zibeela zyotatwe zyaatala zilakonzya kweenda kakunyina kuzungaana muchiindi chakuchita obotu. Ibbazu lya PbC2O4 lili 1 ML mubufwaafwi mpo lili a I-terminal surface ya FAPbI3, aawo Pb nkwaangidwe ku 1 I a 4 O.
Kuti ujane makani manji aatala abubambe bwachiiyo, langa bbuku lya Natural Portfolio Report Abstract lijatikizyidwe aachibalo eechi.
Data yoonse yakajanwa naakuti yakavwuntauzyigwa muchiiyo eechi ilibikkilizyidwe muchibalo chakamwaigwa, antoomwe amumakani aagwasyilizya amafayela aa data iitaninga sika pe. Data iitaninga bamba muchiiyo eechi ilajanika a https://doi.org/10.6084/m9.figshare.2410016440. Data yakusaanguna ilapegwa muchibalo eechi.
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