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Akɛ tɔmɔi ni akɛwoɔ mɔ mli lɛ etsu nii babaoo koni akɛha lead triiodide perovskite hulutsoo be mli tsɔnei lɛ anitsumɔ aya hiɛ, shi nɔ ni tɔmɔi srɔtoi ni yɔɔ α-phase lɛ mli lɛ tsuɔ lɛ mli kã shi faŋŋ; Yɛ biɛ lɛ, wɔkɛ density nitsumɔ he nilee lɛ tsuɔ nii, ni wɔyɔseɔ klɛŋklɛŋ kwraa gbɛ ni formamidine lead triiodide perovskite lɛ fiteɔ kɛjɛɔ α-fase kɛyaa δ-fase lɛ mli lɛ, ni wɔkaseɔ bɔ ni tɔmɔi srɔtoi lɛ tsuɔ nii ehaa yɛ fase tsakemɔ hewalɛ gbɛtsii nii lɛ nɔ lɛ he nii. Nɔ ni jɛ mli ba lɛ tsɔɔ akɛ iodine hei ni bɛ nɔ ko lɛ baanyɛ aha fitemɔ aba ejaakɛ amɛbaa hewalɛ ni tsiɔ α-δ fã tsakemɔ lɛ naa lɛ shi jogbaŋŋ ni amɛyɛ hewalɛ ni baa shi fe fɛɛ yɛ perovskite lɛ hiɛ. Ni akɛ lead oxalate ni nyɛɛɛ atsɔ nu mli lɛ awo perovskite lɛ nɔ lɛ tsiɔ α-phase lɛ fitemɔ naa jogbaŋŋ, ni ehaa iodine lɛ fãmɔ kɛ eshishijee naa. Kɛfata he lɛ, nɛkɛ gbɛ nɛɛ haa hulutsoo be mli nibii ni haa mɔ tsui nyɔɔ emli lɛ baa shi jogbaŋŋ ni ehaa hulutsoo be mli nibii ni tsuɔ nii jogbaŋŋ lɛ yaa hiɛ kɛyashɛɔ 25.39% (ni ji 24.92% ni atsɔɔ mli). Nibii ni akɛwoɔ tsɔne mli lɛ baanyɛ ahi eshishijee 92% lɛ mli lolo beni etsu nii yɛ hewalɛ ni fe fɛɛ mli ŋmɛlɛtswai 550 yɛ kɔɔyɔɔ ni mli wa ni ji 1.5 G lɛ shishi lɛ sɛɛ.
Hewalɛ tsakemɔ nitsumɔ (PCE) ni yɔɔ perovskite hulutsoo be mli wala yibii (PSCs) mli lɛ eshɛ nɔ ni fe fɛɛ ni ji 26%1. Kɛjɛ afi 2015 kɛbaa nɛɛ, ŋmɛnɛŋmɛnɛ beaŋ PSCs lɛ sumɔɔ formamidine triiodide perovskite (FAPbI3) akɛ nɔ ni ŋmɛɔ kane yɛ edɔlɛ ni hi jogbaŋŋ kɛ bandgap ni bɛŋkɛɔ Shockley-Keisser husu ni ji 2,3,4 lɛ hewɔ. Nɔ ni yɔɔ awerɛho ji akɛ, FAPbI3 sinii lɛ tsakeɔ kɛjɛɔ α diŋ mli kɛyaa ŋmɔŋ ni jeee perovskite δ mli yɛ tsu mli dɔlɛ mli5,6. Bɔni afee ni atsĩ delta fã lɛ feemɔ naa lɛ, afee perovskite nibii srɔtoi ni mli wawai. Gbɛ ni atsɔɔ nɔ ayeɔ naagba nɛɛ nɔ kunim ji ni akɛ FAPbI3 afutu methyl ammonium (MA+), cesium (Cs+) kɛ bromide (Br-) ions7,8,9. Shi kɛlɛ, perovskites ni akɛfee ekome lɛ naa amanehulu kɛjɛɔ bandgap mlilɛɛmɔ kɛ foto-induced fã mligbalamɔ mli, ni fiteɔ nitsumɔ kɛ nitsumɔ mli shidaamɔ ni jɛɔ PSCs10,11,12 mli baa lɛ.
Nibii amlipɛimɔi ni afee nyɛsɛɛ nɛɛ etsɔɔ akɛ kristalo kome ni ji FAPbI3 ni nɔ ko bɛ mli lɛ yɛ shifimɔ ni hi jogbaŋŋ yɛ e-crystallinity ni hi jogbaŋŋ kɛ eshai ni baa shi lɛ ahewɔ13,14. No hewɔ lɛ, tɔmɔi ni abaaba shi kɛtsɔ FAPbI3 ni fa babaoo lɛ nɔ lɛ ji gbɛ ni he hiaa ni atsɔɔ nɔ anáa PSCs2,15 ni tsuɔ nii jogbaŋŋ ni yɔɔ shiŋŋ lɛ nɔ. Shi kɛlɛ, yɛ FAPbI3 PSC lɛ nitsumɔ mli lɛ, fitemɔ kɛya hexagonal ŋmɔŋ ni esaaa ni jeee perovskite δ lɛ baanyɛ aba lolo16. Bei pii lɛ, nifeemɔ lɛ jeɔ shishi yɛ shikpɔŋ lɛ nɔ kɛ ŋmaa husui ni nu, dɔlɛ kɛ la nyɛɔ eshɛɔ nɔ yɛ hei babaoo ni efite lɛ ahewɔ17. No hewɔ lɛ, ŋwɛi/ŋmãa passivation he miihia koni akɛha FAPbI318 lɛ fã diŋ lɛ ahi shi. Gbɛjianɔtoi babaoo ni haa mɔ tsui nyɔɔ emli, ni nɔ ni fata he ji perovskites ni baa shi, Lewis mli nibii ni haa mɔ tsui nyɔɔ emli, kɛ ammonium halide ŋmei, etee hiɛ waa yɛ formamidine PSCs19,20,21,22 mli. Kɛbashi ŋmɛnɛ lɛ, nɔ ni miihe ashɛ nikasemɔi fɛɛ kɛ amɛjwɛŋmɔ ema naagbai srɔtoi ni yɔɔ optoelectronic nibii tamɔ nibii ni akɛwoɔ mli lɛ ahe nitsumɔ, gbɛfaŋnɔ ni gbɛɔ eshwaa kɛ band structure yɛ hulutsoo be mli lɛ nɔ22,23,24. Nɔkwɛmɔnɔ, akɛ density functional theory (DFT) tsuɔ nii kɛtsɔɔ bɔ ni hewalɛ ni yɔɔ kɛ bɔ ni hewalɛ ni yɔɔ tɔmɔi srɔtoi amli lɛ yɔɔ ha, ni akɛtsuɔ nii babaoo kɛtsɔɔ bɔ ni afee nɔ ko nɔ ko ahaa lɛ mli20,25,26. Beni tɔmɔi ni yɔɔ mli lɛ ayibɔ baa shi lɛ, bei pii lɛ, bɔ ni tsɔne lɛ damɔ shi shiŋŋ ehaa lɛ yaa hiɛ. Shi, yɛ formamidine PSCs lɛ amli lɛ, esa akɛ gbɛi ni atsɔɔ nɔ atsuɔ tɔmɔi srɔtoi ahe nii yɛ fase stability kɛ fotoelectric nibii anɔ lɛ afee srɔto kwraa. Kɛha wɔ nilee lɛ, shishinumɔ ni he hiaa ni kɔɔ bɔ ni tɔmɔi haa cubic kɛyaa hexagonal (α-δ) fã tsakemɔ kɛ gbɛfaŋnɔ ni ŋwɛi passivation tsuɔ yɛ α-FAPbI3 perovskite fã lɛ shidaamɔ nɔ lɛ he lɛ ji nɔ ni anuuu shishi jogbaŋŋ lolo.
Yɛ biɛ lɛ, wɔjieɔ FAPbI3 perovskite lɛ fitemɔ gbɛ lɛ kpo kɛjɛɔ α-fase diŋ kɛyaa δ-fase ŋmɔŋ mli kɛ hewalɛ ni tɔmɔi srɔtoi ni yɔɔ α-kɛ-δ-fase tsakemɔ lɛ he hewalɛ gbɛtsii nii lɛ nɔ kɛtsɔɔ DFT nɔ lɛ kpo. I nitsumɔi ni bɛ, ni ajieɔ lɛ kpo yɛ sini feemɔ kɛ tsɔne nitsumɔ mli lɛ, atsɔɔ hiɛ akɛ eji nɔ ni baanyɛ aje α-δ fã tsakemɔ lɛ shishi fe fɛɛ. No hewɔ lɛ, wɔkɛ lead oxalate (PbC2O4) ni mli wa ni nu nyɛɛɛ atsɔ mli ni tsofai ni haa mɔ tsui nyɔɔ emli lɛ wo FAPbI3 nɔ kɛtsɔ in situ reaction nɔ. Lead oxalate surface (LOS) lɛ tsiɔ I ŋwɛi ŋtayaai lɛ afeemɔ naa, ni etsĩɔ I ions lɛ agbɛfaa naa kɛji hulutsoo, la, kɛ tsɔne ni haa hulu kpɛɔ lɛ tsirɛ lɛ. Nɔ ni jɛɔ mli baa lɛ haa nɔ ni jɛɔ mli baa lɛ baa shi jogbaŋŋ ni ehaa FAPbI3 PSC nitsumɔ lɛ yaa hiɛ kɛyashɛɔ 25.39% (ni awo he odase akɛ 24.92%). LOS tsɔne ni awooo mli lɛ hiɛ 92% yɛ eshishijee hewalɛ mli beni etsu nii yɛ hewalɛ ni fe fɛɛ (MPP) nɔ fe ŋmɛlɛtswai 550 yɛ kɔɔyɔɔ ni tamɔ nɔ ni ji 1.5 G ni ji radiation lɛ mli.
Wɔfee ab initio akɔntaabuu klɛŋklɛŋ koni wɔna gbɛ ni FAPbI3 perovskite lɛ fiteɔ kɛyaa tsakemɔ kɛjɛɔ α fã lɛ mli kɛyaa δ fã lɛ mli. Kɛtsɔ fã tsakemɔ gbɛjianɔtoo ko ni mli ka shi faŋŋ nɔ lɛ, ana akɛ tsakemɔ ni jɛɔ fãi etɛ ni jaa [PbI6] oktahedron ni yɔɔ cubic α-fa ni ji FAPbI3 lɛ mli kɛyaa fã kome ni yɔɔ ŋwɛigbɛ-jaa [PbI6] oktahedron ni yɔɔ hexagonal δ-fa ni ji a FAPbI3 lɛ mli lɛ ji. fãmɔ 9. Pb-I feɔ tsakpaa yɛ klɛŋklɛŋ gbɛ nɔ (Int-1), ni ehewalɛ gbɛtsii nii lɛ shɛɔ 0.62 eV/cell, taakɛ atsɔɔ yɛ mfoniri 1a lɛ mli lɛ. Kɛji akɛ ajie oktahedron lɛ yɛ [0\(\bar{1}\)1] gbɛ lɛ nɔ lɛ, ŋwɛi ŋta kuku ni yɔɔ ŋwɛi ŋta lɛ mli lɛɛɔ kɛjɛɔ 1×1 kɛyaa 1×3, 1×4 ni naagbee lɛ eboteɔ δ fa lɛ mli. Gbɛ muu lɛ fɛɛ he tsɔɔmɔ mlijaa ji (011)α//(001)δ + [100]α//[100]δ. Kɛjɛ hewalɛ mlijaa mfoniri lɛ mli lɛ, abaanyɛ ana akɛ, yɛ FAPbI3 lɛ δ fã lɛ nucleation sɛɛ yɛ fãi ni nyiɛ sɛɛ nɛɛ amli lɛ, hewalɛ gbɛtsii nii lɛ baa shi fe α fã tsakemɔ lɛ, ni tsɔɔ akɛ fã tsakemɔ lɛ baafee oya. Eyɛ faŋŋ akɛ, klɛŋklɛŋ gbɛ ni atsɔɔ nɔ akudɔɔ fã tsakemɔ lɛ he miihia waa kɛji wɔmiisumɔ ni wɔtsi α-fa lɛ fitemɔ naa.
a Fase tsakemɔ gbɛjianɔtoo kɛjɛɔ abɛku kɛyaa ninejurɔ – FAPbI3 fa diŋ (α-fase), klɛŋklɛŋ Pb-I tsakpaa mligbalamɔ (Int-1) kɛ Pb-I tsakpaa mligbalamɔ kroko (Int-2, Int -3 kɛ Int -4) kɛ fase ŋmɔŋ FAPbI3 (delta fa). b Hewalɛ gbɛtsii nii ni tsiɔ α kɛyaa δ fã tsakemɔ ni ji FAPbI3 lɛ naa lɛ damɔ mligbɛ fãi srɔtoi ni ejaaa lɛ anɔ. Line ni yɔɔ ŋwɛigbɛ lɛ tsɔɔ hewalɛ ni tsiɔ kristalo ni hi jogbaŋŋ (0.62 eV) naa lɛ. c Hewalɛ ni haa shishijee ŋtayaai ni yɔɔ lead perovskite lɛ nɔ lɛ feɔ. Abscissa axis lɛ ji hewalɛ ni tsiɔ α-δ fase tsakemɔ lɛ naa, ni ordinate axis lɛ ji hewalɛ ni haa tɔmɔi baa. Fãi ni akɛ ŋmɔlɔ, ŋmɔŋ kɛ eŋɔli ewo mli lɛ ji henɔ I (EB-high FE ni baa shi), henɔ II (FE ni nɔ kwɔ) kɛ henɔ III (EB-low FE ni baa shi), yɛ amɛteŋ. d Hewalɛ ni haa anáa tɔmɔi VI kɛ LOS ni ji FAPbI3 yɛ nɔyeli lɛ mli lɛ. e I gbɛtsii nii kɛha ion shimɔ yɛ kudɔmɔ kɛ LOS ni ji FAPbI3. f – I ions (ŋwɛi ŋmei) kɛ gLOS FAPbI3 (ŋmei, ŋmei; violet (ŋmei), iodine (mobile iodine)) ni yɔɔ gf nɔyeli lɛ mli lɛ he mfonirifeemɔ ni yɔɔ gf nɔyeli lɛ mli (abɛkugbɛ: ŋwɛi kwɛmɔ; ninejurɔgbɛ: ŋmei, ŋmei); kabɔn; bluu ni mli tse – nitrogen; red – kɔɔyɔɔ ni haa wala yibii; pinki ni mli tse – haidrojin). Akɛ saji ni jɛ mli ba lɛ haa yɛ saji ni jɛ mli ba lɛ faili mli.
No sɛɛ lɛ, wɔkase bɔ ni fãji srɔtoi ni yɔɔ mli lɛ ahe hewalɛ (ni PbFA, IFA, PbI, kɛ IPb antisite ni yɔɔ mli lɛ fata he; Pbi kɛ Ii interstitial atoms; kɛ VI, VFA, kɛ VPb vacancies), ni abuɔ amɛ akɛ amɛji nibii titrii lɛ ahe nii yɛ gbɛjianɔtoo naa. ni kɛ atomik kɛ hewalɛ ŋwɛigbɛ fã lɛ fitemɔ baa lɛ ji nɔ ni atsɔɔ yɛ Mfoniri 1b kɛ Supplementary Table 1. Nɔ ni yɔɔ miishɛɛ ji akɛ, jeee tɔmɔi fɛɛ haa hewalɛ gbɛtsii nii ni yɔɔ α-δ fã tsakemɔ lɛ mli lɛ baa shi (Mfoniri 1b). Wɔheɔ wɔyeɔ akɛ, abuɔ tɔmɔi ni yɔɔ shishitoo hewalɛ ni baa shi kɛ α-δ fã tsakemɔ hewalɛ gbɛtsii nii ni baa shi lɛ fɛɛ akɛ amɛyeɔ fã lɛ shidaamɔ nɔ awui. Taakɛ abɔ he amaniɛ tsutsu lɛ, abuɔ ŋwɛi ni lead yɔɔ mli lɛ akɛ etsuɔ ​​nii jogbaŋŋ kɛha formamidine PSC27. No hewɔ lɛ, wɔkɛ wɔjwɛŋmɔ maa PbI2-ni agbe naa (100) lɛ nɔ yɛ shihilɛi ni lead eyi mli obɔ lɛ shishi. Atsɔɔ tɔmɔi ni yɔɔ ŋwɛigbɛ lɛ amli tɔmɔi lɛ ahe hewalɛ ni yɔɔ ŋwɛigbɛ lɛ mli yɛ mfoniri 1c kɛ Supplementary Table 1. Kɛ damɔ hewalɛ gbɛtsii nii (EB) kɛ fase tsakemɔ nifeemɔ hewalɛ (FE) lɛ nɔ lɛ, aja tɔmɔi nɛɛ amli awo henɔi etɛ mli. Type I (low EB-high FE): Eyɛ mli akɛ IPb, VFA kɛ VPb haa hewalɛ ni tsiɔ gbɛ kɛyaa fã tsakemɔ mli lɛ baa shi jogbaŋŋ moŋ, shi amɛyɛ hewalɛ ni nɔ kwɔ ni akɛfeɔ nii. No hewɔ lɛ, wɔheɔ wɔyeɔ akɛ nɛkɛ tɔmɔi nɛɛ bɛ hewalɛ ko kwraa yɛ fase tsakemɔi anɔ ejaakɛ amɛfɔɔɔ feemɔ. EB ni nɔ kwɔ: Yɛ α-δ fã tsakemɔ hewalɛ gbɛtsii nii ni etee hiɛ lɛ hewɔ lɛ, anti-site tɔmɔi PbI, IFA kɛ PbFA lɛ efiteee fã ni yɔɔ α-FAPbI3 perovskite lɛ mli lɛ. EB-low FE): VI, Ii kɛ Pbi tɔmɔi ni yɔɔ shishitoo hewalɛ ni baa shi lɛ baanyɛ aha fã ni ji diŋ lɛ afite. Titri lɛ, kɛ akɛ FE kɛ EB VI ni baa shi fe fɛɛ lɛ ha lɛ, wɔheɔ wɔyeɔ akɛ gbɛ ni hi fe fɛɛ ji ni ajie I nitsumɔi ni bɛ lɛ shi.
Bɔni afee ni VI lɛ aba shi lɛ, wɔfee PbC2O4 ni mli eyi obɔ lɛ koni wɔkɛha FAPbI3 lɛ hiɛ aya hiɛ. Kɛ akɛto ŋmeii ni haa mɔ he jɔɔ lɛ ahe tamɔ phenylethylammonium iodide (PEAI) kɛ n-octylammonium iodide (OAI) lɛ, PbC2O4, ni bɛ halogen ions ni nyiɛɔ lɛ, ji nɔ ni yɔɔ shiŋŋ yɛ tsofafeemɔ mli, enyɛŋ etsɔ nu mli, ni kɛ́ atswa lɛ lɛ, egboɔ oya. Nibii ni hi jogbaŋŋ ni haa ŋwɛi ŋmɔtɔ kɛ perovskite lɛ tsɔne ni haa hulu kpɛɔ lɛ damɔ shi shiŋŋ. PbC2O4 ni yɔɔ nu mli lɛ ji 0.00065 g/L pɛ, ni eba shi fe PbSO428 po. Nɔ ni he hiaa fe fɛɛ lɛ, abaanyɛ asaa LOS ni mli eyi obɔ kɛ nɔ ni yɔɔ ekome lɛ he blɛoo yɛ perovskite sinii anɔ kɛtsɔ in situ reactions nɔ (kwɛmɔ shishigbɛ). Wɔfee DFT simulations ni kɔɔ interfacial bonding ni yɔɔ FAPbI3 kɛ PbC2O4 teŋ lɛ he taakɛ atsɔɔ yɛ Supplementary Figure 1 lɛ mli lɛ. Wɔna akɛ LOS lɛ haaa VI tɔmɔi lɛ afeemɔ hewalɛ yaa hiɛ kɛ 0.69–1.53 eV pɛ (Mfoniri 1d), shi moŋ ehaa I nitsumɔ hewalɛ hu yaa hiɛ yɛ fãmɔ ŋwɛi kɛ kpojee ŋwɛi (Mfoniri 1e). Yɛ klɛŋklɛŋ gbɛhe lɛ mli lɛ, I ions lɛ fãa kɛtsɔɔ perovskite lɛ hiɛ, ni eshiɔ VI ions lɛ yɛ lattice shihilɛ mli ni hewalɛ gbɛtsii nii ni ji 0.61 eV yɔɔ mli. Yɛ be mli ni LOS lɛ je shishi lɛ, yɛ steric hindrance lɛ he hewalɛ hewɔ lɛ, hewalɛ ni haa I ions lɛ fãa kɛyaa he kroko lɛ yaa hiɛ kɛyashɛɔ. 1.28 eV. Yɛ be mli ni I ions lɛ shiɔ perovskite lɛ hiɛ lɛ, hewalɛ gbɛtsii nii ni yɔɔ VOC lɛ mli lɛ hu nɔ kwɔ fe nɔkwɛmɔnɔ ni kudɔɔ lɛ (Mfoniri 1e). Atsɔɔ I ion fãmɔ gbɛi ni yɔɔ nɔyeli mli kɛ LOS FAPbI3 lɛ ahe mfonirii ni yɔɔ mfoniri 1 f kɛ g lɛ mli. Nɔ ni jɛ mli ba lɛ tsɔɔ akɛ LOS baanyɛ atsĩ VI tɔmɔi lɛ afeemɔ kɛ I lɛ sɛɛkuu lɛ naa, ni no baatsi α kɛ δ fã tsakemɔ lɛ naa.
Akɛ bɔ ni oxalic acid kɛ FAPbI3 perovskite tsuɔ nii amɛhaa lɛ akwɛ. Beni akɛ oxalic acid kɛ FAPbI3 mli tsofai lɛ futu mli sɛɛ lɛ, ŋmɔtɔ ni yɔɔ ŋmɔtɔ babaoo ba, taakɛ atsɔɔ yɛ Mfoniri ni Akɛfata He 2 lɛ mli lɛ. mg/mL, taakɛ atsɔɔ yɛ Supplementary Figure 5 lɛ mli lɛ, enɛ haa sɛɛ mli nitsumɔ lɛ feɔ mlɛo ejaakɛ IPA, akɛ nɔ ni afɔɔ nitsumɔ ni haa mɔ tsui nyɔɔ emli lɛ, efiteee peroyonski be kukuoo lɛ. No hewɔ lɛ, kɛtsɔ perovskite sini lɛ ni akɛwoɔ oxalic acid mli loo spin-coating oxalic acid mli lɛ nɔ lɛ, abaanyɛ ana PbC2O4 ni mli tse ni mli wa oya yɛ perovskite sini lɛ nɔ taakɛ tsofafeemɔ mli equation ni nyiɛ sɛɛ nɛɛ tsɔɔ lɛ: H2C2O4 + FAPbI +3. Abaanyɛ ajie FAI awo IPA mli ni no aha ajie yɛ be mli ni ahoɔ nii lɛ. LOS lɛ mli ŋmɔlɔ lɛ baanyɛ akudɔ kɛtsɔ be ni akɛtsuɔ nii kɛ nɔ ni tsɔɔ hiɛ lɛ mli nibii ni yɔɔ mli lɛ nɔ.
Atsɔɔ mfoniri ni akɛkwɛɔ nibii bibii ni akɛkwɛɔ nibii bibii amli (SEM) ni kɔɔ nɔkwɛmɔ kɛ LOS perovskite sinii ahe lɛ mli yɛ mfoniri 2a,b lɛ mli. Nɔ ni jɛ mli ba lɛ tsɔɔ akɛ, ato perovskite lɛ hiɛ he mfoniri lɛ he gbɛjianɔ jogbaŋŋ, ni akɛ nibii bibii babaoo ewo ŋmaa lɛ hiɛ, ni esa akɛ edamɔ shi aha PbC2O4 ŋta ni in-situ reaction lɛ feɔ lɛ. LOS perovskite sini lɛ yɛ ŋwɛi ni yɔɔ ŋmɔlɔŋmɔlɔ fioo (Mfoniri ni fata he 6) kɛ nu ni kɛ ehe kpaa gbee lɛ he ŋwɛigbɛ ni da fe nɔ ni kudɔɔ sini lɛ (Mfoniri ni fata he 7). Akɛ electron microscopy (HR-TEM) ni haa hulu kpɛɔ waa lɛ tsu nii koni akɛyoo srɔtofeemɔ ni yɔɔ nɔ ni akɛfee lɛ hiɛ lɛ teŋ. Kɛ akɛto sini ni kudɔɔ nii lɛ he (Mfoniri 2c) lɛ, anaa ŋwɛi ŋta ni yɔɔ mlɛo ni tamɔ 10 nm lɛ jogbaŋŋ yɛ LOS perovskite lɛ nɔ (Mfoniri 2d). Kɛtsɔ ŋwɛi ŋta ni yɔɔ duŋ mli ni akɛkwɛɔ nibii bibii ni yɔɔ duŋ mli (HAADF-STEM) nɔ lɛ nɔ lɛ, abaanyɛ ana FAPbI3 kristalo kpokpai kɛ PbC2O4 kpokpai ni bɛ su lɛ ni yɔɔ lɛ faŋŋ (Mfoniri ni fata he 8). Nibii ni yɔɔ perovskite lɛ hiɛ yɛ oxalic acid helatsamɔ sɛɛ lɛ ji nɔ ni X-ray fotoelektron spectroscopy (XPS) susumɔi tsɔɔ, taakɛ atsɔɔ yɛ mfoniri 2e–g lɛ mli lɛ. Yɛ mfoniri 2e lɛ mli lɛ, C 1s yitsei ni miihe ashɛ 284.8 eV kɛ 288.5 eV lɛ fata CC kɛ FA okadi pɔtɛɛ lɛ he, yɛ gbɛ kome nɔ. Kɛ akɛto nɔ ni kudɔɔ tsɔne lɛ he lɛ, LOS tsɔne lɛ jieɔ nɔ ni fe fɛɛ ni fata he lɛ kpo yɛ 289.2 eV, ni akɛwo C2O42- mli. 531.7 eV, 532.5 eV, kɛ 533.4 eV, ni kɛ COO ni ajie lɛ kpo lɛ kpãa gbee, C=O ni ji oxalate kui 30 kɛ O atoms ni yɔɔ OH2e lɛ mli lɛ (Fig. ). )). Kɛha nɔkwɛmɔnɔ ni kudɔɔ lɛ, ana O 1s yitso bibioo ko pɛ, ni abaanyɛ akɛto oxygen chemisorbed ni yɔɔ ŋwɛi lɛ he. 138.4 eV kɛ 143.3 eV, yɛ gbɛ kome nɔ. Wɔna akɛ LOS perovskite lɛ jieɔ Pb yitso lɛ shi ni miihe ashɛ 0.15 eV lɛ kpo kɛyaa hewalɛ ni nɔ kwɔ ni akɛfiɔ nii ahe lɛ nɔ, ni tsɔɔ akɛ C2O42- kɛ Pb atoms lɛ ateŋ tsakpaa ni mli wa waa (Mfoniri 2g).
a SEM mfonirii ni kɔɔ nɔyeli he kɛ b LOS perovskite sinii, ŋwɛi kwɛmɔ. c Nibii ni yɔɔ ŋwɛi ni tsɔɔ ŋwɛi ŋwɛi (HR-TEM) ni akɛkwɛɔ nibii amli kɛ d LOS perovskite sinii. XPS ni yɔɔ ŋwɛi ni ji e C 1s, f O 1s kɛ g Pb 4f perovskite sinii. Akɛ saji ni jɛ mli ba lɛ haa yɛ saji ni jɛ mli ba lɛ faili mli.
Taakɛ DFT hetooi lɛ tsɔɔ lɛ, atsɔɔ hiɛ atsɔɔ akɛ VI tɔmɔi kɛ I shifãa lɛ haa fã tsakemɔ ni jɛɔ α kɛyaa δ lɛ baa mlɛo. Amaniɛbɔi ni eho lɛ etsɔɔ akɛ I2 jeɔ kpo oya kɛjɛɔ PC-based perovskite sinii amli yɛ fotoimmersion be mli beni ajie sinii lɛ awo la kɛ la ni mli edɔ mli lɛ sɛɛ31,32,33. Kɛha bɔ ni lead oxalate lɛ tsuɔ nii ehaa yɛ perovskite lɛ α-phase lɛ nɔ lɛ nɔmimaa lɛ, wɔkɛ nɔ ni kudɔɔ lɛ kɛ LOS perovskite sinii lɛ wo glase tsɛnsii ni mli tse ni toluene yɔɔ mli lɛ amli, ni no sɛɛ lɛ wɔkɛ hulu la 1 shwie amɛnɔ kɛyashi ŋmɛlɛtswai 24. Wɔsusu bɔ ni la ni ji ultraviolet kɛ la ni anaa (UV-Vis) lɛ shwieɔ la lɛ he. ) toluene mli nu, taakɛ atsɔɔ yɛ Mfoniri 3a lɛ mli lɛ. Kɛ akɛto nɔkwɛmɔnɔ ni kudɔɔ lɛ he lɛ, ana I2 ni ajieɔ kɛjɛɔ mli lɛ mli hewalɛ ni baa shi kwraa yɛ LOS-perovskite lɛ mli, ni tsɔɔ akɛ LOS ni yɔɔ kuku lɛ baanyɛ atsĩ I2 ni ajieɔ kɛjɛɔ perovskite sini lɛ mli lɛ naa yɛ be mli ni akɛwoɔ la mli lɛ. Atsɔɔ mfonirii ni kɔɔ mɛi ni egbɔ lɛ akudɔmɔ kɛ LOS perovskite sinii ahe yɛ mfoniri 3b kɛ c lɛ mli nibii ni akɛwoɔ mli lɛ amli. LOS perovskite lɛ yɛ ediŋŋ lolo, yɛ be mli ni sini ni kudɔɔ sini lɛ mli babaoo etsɔ ŋmɔŋ. Atsɔɔ UV–ni anaa ni jieɔ sini ni awo mli lɛ mli lɛ yɛ Figs. 3b, ak. Wɔna akɛ, α ni yɔɔ sini ni kudɔɔ sini lɛ mli lɛ mli lɛ ba shi yɛ faŋŋ mli. Asusu X-ray he koni akɛŋmala bɔ ni kristalo lɛ tsake eha lɛ he saji. Yɛ ŋmɛlɛtswai 24 ni akɛkpɛɔ la sɛɛ lɛ, perovskite ni kudɔɔ lɛ lɛ jie δ-phase okadi ni mli wa ni ji ŋmɔŋ (11.8°) lɛ kpo, yɛ be mli ni LOS perovskite lɛ hiɛɔ phase diŋ kpakpa mli lolo (Mfoniri 3d).
UV-ni anaa lɛ mli nibii ni haa mɔ tsui nyɔɔ emli ni ji toluene solutions ni akɛ sini ni kudɔɔ sini lɛ kɛ LOS sini lɛ woɔ hulu la 1 shishi ŋmɛlɛtswai 24 lɛ. Nɔ ni akɛwo mli lɛ tsɔɔ tsinsii ko ni akɛ toluene ni falɛ tamɔ nakai wo sini lɛ eko fɛɛ eko mli. b UV-Vis ni shwieɔ shi yɛ sini ni kudɔɔ nii lɛ mli kɛ c LOS sini dani ŋmɛlɛtswai 24 ni akɛwoɔ nu mli yɛ hulu la 1 shishi kɛ sɛɛ mli. Nɔ ni akɛwo mli lɛ tsɔɔ kaa sini lɛ mfoniri. d X-ray diffraction gbɛjianɔtoi ni kɔɔ nɔyeli kɛ LOS sinii ahe dani kɛ sɛɛ mli 24 h ni ajieɔ lɛ kpo lɛ. SEM mfonirii ni kudɔɔ sini e kɛ sini f LOS yɛ ŋmɛlɛtswai 24 ni akɛjieɔ lɛ kpo lɛ sɛɛ. Akɛ saji ni jɛ mli ba lɛ haa yɛ saji ni jɛ mli ba lɛ faili mli.
Wɔfee skanning electron microscopy (SEM) susumɔi koni wɔkɛkwɛ tsakemɔi ni baa yɛ perovskite sini lɛ mli yɛ ŋmɛlɛtswai 24 ni akɛ la kpɛɔ lɛ sɛɛ, taakɛ atsɔɔ yɛ mfoniri 3e,f lɛ mli lɛ. Yɛ sini ni kudɔɔ lɛ mli lɛ, akpata ŋmaa wuji ahiɛ ni atsake amɛ afee ŋmeii bibii, ni kɛ δ-phase product FAPbI3 (Fig. 3e) lɛ su lɛ kpãa gbee. Kɛha LOS sinii lɛ, perovskite ŋmaa lɛ hiɔ shi yɛ shihilɛ kpakpa mli (Mfoniri 3f). Nɔ ni jɛ mli ba lɛ ma nɔ mi akɛ, I ni laajeɔ lɛ haa tsakemɔ ni jɛɔ fã diŋ lɛ mli kɛyaa fã ni ji ŋmɔŋ lɛ mli lɛ baa, yɛ be mli ni PbC2O4 haa fã diŋ lɛ hiɔ shi, ni ehaa I ni laajeɔ lɛ naa. yɛ be kome mli lɛ, ejieɔ iodine ni efeɔ VI. Taakɛ DFT lɛ gba afɔ̃ shi lɛ, LOS baanyɛ atsĩ VI tɔmɔi lɛ afeemɔ naa ni etsĩ I ions lɛ fãmɔ kɛmiiya perovskite lɛ nɔ lɛ naa.
Kɛfata he lɛ, akase bɔ ni PbC2O4 ŋtayaa lɛ tsuɔ nii ehaa yɛ perovskite sinii ni yɔɔ kɔɔyɔɔ mli lɛ ahe lɛ mli (fɔmɔ ni falɛ ji 30-60%). Taakɛ atsɔɔ yɛ Mfoniri ni Akɛfata He 9 lɛ mli lɛ, LOS perovskite lɛ ji ediŋŋ lolo yɛ gbii 12 sɛɛ, yɛ be mli ni sini ni kudɔɔ nii lɛ batsɔ ŋmɔŋ. Yɛ XRD susumɔi amli lɛ, sini ni kudɔɔ lɛ tsɔɔ ŋwɛi ŋta ni mli wa yɛ 11.8° ni kɛ FAPbI3 δ fã lɛ kpãa gbee, yɛ be mli ni LOS perovskite lɛ hiɛɔ α fã diŋ lɛ mli jogbaŋŋ (Mfoniri ni fata he 10).
Akɛ hulutsoo ni yɔɔ shiŋŋ (PL) kɛ hulutsoo ni akɛtsuɔ nii yɛ be mli (TRPL) tsu nii koni akɛkase bɔ ni lead oxalate lɛ tsuɔ nii ehaa yɛ perovskite lɛ nɔ lɛ he nii. Yɛ Fig. Fig. 4a lɛ tsɔɔ akɛ LOS sini lɛ eha PL hewalɛ etee hiɛ. Yɛ PL shikpɔŋ he mfoniri lɛ mli lɛ, LOS sini lɛ mli hewalɛ ni fe 10 × 10 μm2 lɛ fɛɛ nɔ lɛ nɔ kwɔ fe sini ni kudɔɔ lɛ (Mfoniri ni fata he 11), ni tsɔɔ akɛ PbC2O4 lɛ haa perovskite sini lɛ feɔ nɔ kome. Akɛ TRPL fitemɔ lɛ he nitsumɔ kome ni ji eksponensial nitsumɔ kome (Mfoniri 4b) lɛ tsɔɔ nɔ ni tsɔɔ tsɔne ni hiɛɔ nii lɛ wala be lɛ mli. LOS sini lɛ wala be ji 5.2 μs, ni sɛɛ tsɛɔ kwraa fe sini ni kudɔɔ lɛ ni wala be ji 0.9 μs, ni tsɔɔ akɛ ŋwɛi nɔ ni bɛ la ni tsoɔ lɛ sɛɛkuu lɛ eba shi.
PL ni yɔɔ shiŋŋ kɛ b-spectra ni ji be kukuoo mli PL ni ji perovskite sinii ni yɔɔ glase shishi lɛ. c SP curve ni ji tsɔne lɛ (FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au). d EQE spectrum kɛ Jsc EQE spectrum ni akɛfee ekome kɛjɛ tsɔne ni tsuɔ nii jogbaŋŋ fe fɛɛ lɛ mli. d La ni tsoɔ waa ni yɔɔ perovskite tsɔne ko mli lɛ damɔ Voc mfoniri lɛ nɔ. f MKRC mlipɛimɔ ni afɔɔ feemɔ ni akɛ ITO/PEDOT:PSS/perovskite/PCBM/Au bu ni mli tse tsuɔ nii. VTFL ji tsɔne ni fa fe fɛɛ ni akɛwoɔ tsɔne mli. Wɔjɛ saji nɛɛ amli wɔbu tsɔne ni akɛwoɔ mɔ mli lɛ (Nt) lɛ he akɔntaa. Akɛ saji ni jɛ mli ba lɛ haa yɛ saji ni jɛ mli ba lɛ faili mli.
Kɛha bɔ ni lead oxalate layer lɛ tsuɔ nii ehaa yɛ tsɔne lɛ nitsumɔ nɔ lɛ he nikasemɔ lɛ, akɛ kusum nifeemɔ ko ni atsɛɔ lɛ FTO/TiO2/SnO2/perovskite/spiro-OMeTAD/Au lɛ tsu nii. Wɔkɛ formamidine chloride (FACl) tsuɔ nii akɛ nɔ ni akɛfataa perovskite hiɛnyiɛlɔ lɛ he yɛ methylamine hydrochloride (MACl) najiaŋ koni wɔnine ashɛ tsɔne lɛ nitsumɔ ni hi jogbaŋŋ nɔ, ejaakɛ FACl baanyɛ aha kristalo ni hi jogbaŋŋ aha ni etsi ehe kɛjɛ band gap ni yɔɔ FAPbI335 lɛ mli lɛ he (kwɛmɔ Mfonirii ni Akɛtoɔ He lɛ kɛ Mfonirii ni Akɛto He lɛ). ). 12-14 lɛ nɔ). Ahala IPA akɛ nɔ ni gbeɔ tsofa lɛ ejaakɛ ehaa kristalo ni hi jogbaŋŋ kɛ gbɛtsɔɔmɔ ni asumɔɔ yɛ perovskite sinii amli kɛ akɛto diethyl ether (DE) loo chlorobenzene (CB)36 he (Mfonirii ni fata he 15 kɛ 16). Akɛ PbC2O4 lɛ mli tsɔne lɛ tsu nii jogbaŋŋ koni ekɛ tsɔne ni haa mɔ he jɔ̃ɔ ehe lɛ kɛ tsɔne ni akɛwoɔ tsɔne mli lɛ afee ekome jogbaŋŋ kɛtsɔ oxalic acid lɛ mli tsɔne lɛ tsakemɔ nɔ (Supplementary Figure 17). Atsɔɔ ŋmɛnɛŋmɛnɛ beaŋ density (CD) curves kɛha nɔkwɛmɔ kɛ LOS nibii lɛ yɛ mfoniri 4c lɛ mli, ni ajie parameters ni ajie lɛ kpo yɛ Supplementary Table 3. Maximum power conversion efficiency (PCE2c%)43. 25.75 mA cm-2 (25.74 mA cm-2), Voc 1.16 V (1.16 V) kɛ sɛɛkuu (hiɛ) skan. Nibii ni haa mɔ tsui nyɔɔ emli (FF) lɛ ji 78.40% (76.69%). 25.77 mA cm-2, Voc ji 1.18 V, FF ji 83.50% (81.52%) kɛjɛ sɛɛgbɛ (hiɛ Scan kɛyaa). LOS tsɔne lɛ ná fotovoltaik nitsumɔ ni yɔɔ odaseyeli ni ji 24.92% yɛ fotovoltaik laboratori ko ni ji etɛ ni anyɛɔ akɛ he fɔ̃ɔ nɔ lɛ mli (Mfoniri ni fata he 19). 24.90 mA cm-2 (kudɔmɔ) kɛ 25.18 mA cm-2 (LOS PSC), ni kɛ Jsc ni asusu yɛ AM 1.5 G spectrum ni ji shishitoo mla lɛ mli lɛ kpãa gbee jogbaŋŋ (Fig. .4d). ) . Atsɔɔ PCEs ni asusu lɛ mlijaa kɛha nɔkwɛmɔ kɛ LOS PSCs yɛ Mfoniri 20 ni fata he lɛ mli.
Taakɛ atsɔɔ yɛ mfoniri 4e lɛ mli lɛ, abu wekukpaa ni kã Voc kɛ la hewalɛ teŋ lɛ he akɔntaa koni akɛkase bɔ ni PbC2O4 lɛ tsuɔ nii ehaa yɛ ŋwɛi ŋta ni yeɔ ebuaa lɛ nɔ lɛ he nii. 1.16 kBT/sq, ni ji 1.31 kBT/sq, ni maa nɔ mi akɛ LOS lɛ he yɛ sɛɛnamɔ kɛha ŋwɛi nibii ni akɛfeɔ ekome ekoŋŋ kɛtsɔ decoys nɔ lɛ naatsii. Wɔkɛ ŋwɛi charge ni haa mɔ tsui nyɔɔ emli (SCLC) he ŋaalee tsuɔ nii koni wɔkɛsusu bɔ ni perovskite sini ko mli tɔmɔi lɛ fa ha lɛ he kɛtsɔ IV ni yɔɔ duŋ ni yɔɔ bu mli tsɔne ko mli lɛ he susumɔ nɔ (ITO/PEDOT:PSS/perovskite/spiro-OMeTAD/Au) taakɛ atsɔɔ yɛ mfoniri lɛ mli lɛ nɔ. 4f Tsɔɔmɔ. Akɛ tsɔne ni ji Nt = 2ε0εVTFL/eL2 lɛ buɔ tsɔne lɛ mli tsɔne lɛ he akɔntaa, he ni ε ji perovskite sini lɛ mli tsɔne ni haa hulutsoo lɛ yaa hiɛ lɛ, ε0 ji tsɔne ni haa tsɔne lɛ mli tsɔne lɛ shɛɔ shi lɛ, VTFL ji tsɔne lɛ mli tsɔne lɛ mli hewalɛ ni haa mɔ tsui nyɔɔ emli lɛ, e ji charge lɛ, L ji pero6ski sini lɛ mli tsɔne lɛ mli tsɔne lɛ ( pero6ski n sini lɛ mli tsɔne lɛ). Akɛ VOC tsɔne lɛ mli naagbai lɛ abuɔ he akɔntaa akɛ 1.450 × 1015 cm–3, ni baa shi fe tsɔne ni kudɔɔ nii lɛ mli naagbai lɛ, ni ji 1.795 × 1015 cm–3.
Akɛ tsɔne ni akɛwooo mli lɛ ka he ni hewalɛ ni fe fɛɛ (MPP) yɔɔ lɛ yɛ hulutsoo be muu fɛɛ shishi yɛ nitrogen shishi koni akɛkwɛ bɔ ni etsuɔ ​​nii be kakadaŋŋ lɛ mli (Mfoniri 5a). Yɛ ŋmɛlɛtswai 550 sɛɛ lɛ, LOS tsɔne lɛ tee nɔ etsu nii jogbaŋŋ fe fɛɛ lɛ mlijaa 92 lolo, yɛ be mli ni tsɔne ni kudɔɔ nii lɛ nitsumɔ eba shi kɛyashɛ shishijee nitsumɔ lɛ mlijaa 60. Akɛ nibii ni yɔɔ tsɔne momo lɛ mli lɛ amlijaa lɛ susu kɛtsɔ be-kɛ-fãmɔ ni ji enyɔ lɛ nɔ ion mass spectrometry (ToF-SIMS) (Mfoniri 5b, c) nɔ. Abaanyɛ ana iodine babaoo ni ebua naa yɛ ŋwɛi shika tsuru nɔkwɛmɔ he lɛ. Shihilɛi ni yɔɔ inert gas hebuu mli lɛ jieɔ nibii ni fiteɔ shihilɛ tamɔ ŋmɔtɔ kɛ kɔɔyɔɔ kpakpa kɛjɛɔ mli, ni tsɔɔ akɛ mligbɛ gbɛjianɔtoi (ni ji, ion shimɔ) ji nɔ ni kɛbaa. Taakɛ ToF-SIMS hetooi lɛ tsɔɔ lɛ, ana I- kɛ AuI2- ions yɛ Au electrode lɛ mli, ni tsɔɔ bɔ ni I lɛ gbɛɔ eshwaa kɛjɛɔ perovskite lɛ mli kɛyaa Au mli. I- kɛ AuI2- ions ni yɔɔ tsɔne ni kudɔɔ nii lɛ mli lɛ okadi hewalɛ lɛ fa fe VOC nɔkwɛmɔnɔ lɛ nɔ lɛ aaafee shii 10. Amaniɛbɔi ni eho lɛ etsɔɔ akɛ ion mlibotemɔ baanyɛ aha spiro-OMeTAD bu lɛ mli hewalɛ aba shi oya kɛ tsofa ni fiteɔ electrode layer lɛ nɔ, ni no haa nɔ ni yɔɔ tsɔne lɛ mli lɛ fiteɔ. Ajie Au electrode lɛ ni akɛ klorobenzene tsofa tsuu spiro-OMeTAD fã lɛ he kɛjɛ shishigbɛ lɛ mli. No sɛɛ lɛ, wɔkɛ X-ray diffraction (GIXRD) (Mfoniri 5d) tsu nii kɛtsɔɔ sini lɛ mli. Nɔ ni jɛ mli ba lɛ tsɔɔ akɛ sini ni kudɔɔ sini lɛ yɛ ŋwɛi ŋta ni yɔɔ faŋŋ ni ji 11.8°, yɛ be mli ni ŋwɛi ŋta hee ko ejeee kpo yɛ LOS nɔkwɛmɔnɔ lɛ mli. Nɔ ni jɛ mli ba lɛ tsɔɔ akɛ I ions ni laajeɔ babaoo yɛ sini ni kudɔɔ sini lɛ mli lɛ kɛ δ fã lɛ baa, yɛ be mli ni yɛ LOS sini lɛ mli lɛ, atsĩɔ gbɛ nɛɛ naa faŋŋ.
575 ŋmɛlɛtswai ni yaa nɔ MPP sɛɛnyiɛmɔ ni kɔɔ tsɔne ko ni atsĩko naa yɛ nitrogen kɔɔyɔɔ mli kɛ hulu la 1 ni UV filta bɛ mli lɛ he. ToF-SIMS mlijaa b I- kɛ c AuI2- ions yɛ LOS MPP kudɔmɔ tsɔne kɛ dalɛ tsɔne mli. Nibii ni yɔɔ ŋmɔlɔŋmɔlɔ, eŋɔli kɛ ŋmɔlɔŋmɔlɔ lɛ kɛ Au, Spiro-OMeTAD kɛ perovskite lɛ kpãa gbee. d GIXRD ni ji perovskite sini lɛ yɛ MPP kaa lɛ sɛɛ. Akɛ saji ni jɛ mli ba lɛ haa yɛ saji ni jɛ mli ba lɛ faili mli.
Asusu bɔ ni hulutsoo be lɛ yaa nɔ ehaa lɛ he koni akɛma nɔ mi akɛ PbC2O4 baanyɛ atsĩ ion shimɔ naa (Supplementary Figure 21). Akɛ hewalɛ ni tsuɔ nii (Ea) ni kɔɔ ion fãmɔ he lɛ ji nɔ ni akɛsusuɔ tsakemɔ ni baa FAPbI3 sini lɛ mli yɛ hulutsoo bei srɔtoi amli (T) lɛ he, ni akɛ Nernst-Einstein wekukpaa lɛ tsuɔ nii: σT = σ0exp(−Ea/kBT), he ni σ0 ji nɔ ni tsakeee, kB ji nɔ ni tsakeee lɛ. Wɔnaa Ea sɛɛnamɔ lɛ kɛjɛɔ ln(σT) kɛ 1/T lɛ slope lɛ mli, ni ji 0.283 eV kɛha nɔyeli lɛ kɛ 0.419 eV kɛha LOS tsɔne lɛ.
Yɛ kukufoo mli lɛ, wɔkɛ tsɔɔmɔ gbɛjianɔtoo ko haa koni akɛyoo gbɛ ni FAPbI3 perovskite lɛ fiteɔ lɛ kɛ hewalɛ ni tɔmɔi srɔtoi ni yɔɔ α-δ fã tsakemɔ lɛ nɔ lɛ náa hewalɛ gbɛtsii nii lɛ nɔ. Yɛ nɛkɛ tɔmɔi nɛɛ ateŋ lɛ, VI tɔmɔi lɛ ji nɔ ni atsɔɔ hiɛ atsɔɔ akɛ ebaaha fã tsakemɔ ko aba kɛjɛ α kɛya δ mli oya. Akɛ PbC2O4 ni nu nyɛɛɛ atsɔ mli ni tsofai tsuɔ nii jogbaŋŋ lɛ woɔ mli koni ekɛha FAPbI3 α-fase lɛ ahi shi kɛtsɔ I vacancies lɛ afeemɔ kɛ I ions lɛ fãmɔ ni tsiɔ naa lɛ nɔ. Nɛkɛ gbɛ nɛɛ haa hulutsoo be mli nibii ni bɛ hulutsoo be mli lɛ baa shi jogbaŋŋ, ehaa hulutsoo be mli tsɔnei lɛ tsuɔ nii jogbaŋŋ kɛyashɛɔ 25.39%, ni ehaa nitsumɔ lɛ yaa hiɛ. Nɔ ni jɛ mli ba lɛ haa gbɛtsɔɔmɔ koni anyɛ ana formamidine PSCs ni tsuɔ nii jogbaŋŋ ni yɔɔ shiŋŋ lɛ kɛtsɔ α kɛ δ fã tsakemɔ ni tɔmɔ baa lɛ ni tsiɔ naa lɛ nɔ.
Akɛ tsofa ni ji titanium (IV) (TTIP, 99.999%) lɛ he kɛjɛ Sigma-Aldrich dɛŋ. Ahe nu mli nu (HCl, 35.0–37.0%) kɛ ethanol (ni nu bɛ mli) kɛjɛ Guangzhou tsofafeemɔ nitsumɔhe lɛ. Akɛ SnO2 (15 wt% tin (IV) okside ni mli egbɛ eshwa) lɛ he kɛjɛ Alfa Aesar dɛŋ. Akɛ tsofa ni ji lead (II) (PbI2, 99.99%) lɛ he kɛjɛ TCI Shanghai (China) lɛ dɛŋ. Formamidine iodide (FAI, ≥99.5%), fɔmidine kloraid (FACl, ≥99.5%), methylamine hydrochloraide (MACl, ≥99.5%), 2,2′,7,7′-tetrakis-(N, N-robithoxy′)-9-9)- 99.5%), lithium bis (trifluoromethane) sulfonylimide (Li-TFSI, 99.95%), 4-tert -butylpyridine (tBP, 96%) ni ahé kɛjɛ Xi’an Polymer Light Technology Company (China) lɛ dɛŋ. N,N-dimethylformamide (DMF, 99.8%), dimethyl sulfoxide (DMSO, 99.9%), isopropyl dãa (IPA, 99.8%), klorobenzene (CB, 99.8%), asetonitrile (ACN). Ahe kɛjɛ Sigma-Aldrich dɛŋ. Akɛ oksalik asidi (H2C2O4, 99.9%) lɛ he kɛjɛ Macklin dɛŋ. Akɛ tsofai lɛ fɛɛ tsu nii bɔ ni aná lɛ ni tsakemɔi krokomɛi bako mli.
ITO loo FTO shishigbɛ nibii (1.5 × 1.5 cm2) lɛ ji nɔ ni akɛ tsɔne ni akɛjieɔ muji, acetone, kɛ ethanol tsu nii kɛtsu nii minitii 10, ni no sɛɛ lɛ, agbi yɛ nitrogen faa ko shishi. Akɛ titanium diisopropoxybis (acetylacetonate) ni yɔɔ ethanol (1/25, v/v) mli ni akɛwoɔ 500 °C mli minitii 60 lɛ tsu nii kɛwo FTO shishitoo nɔ ko nɔ. Akɛ nu ni mli ewo muji lɛ wo SnO2 colloidal gbɛfaŋnɔ lɛ mli yɛ 1:5 mli. Yɛ shikpɔŋ ni he tse ni akɛ UV ozone etsu nii minitii 20 lɛ nɔ lɛ, akɛ SnO2 nanoparticles ni mli tseee lɛ wo 4000 rpm mli sɛkɛndii 30, ni no sɛɛ lɛ, akɛwo 150 °C mli minitii 30. 275.2 mg FAI, 737.6 mg PbI2 kɛ FACl (20 mol%) ni akɛwoɔ DMF/DMSO (15/1) ni akɛfutu mli lɛ mli. Akɛ perovskite fã lɛ saa kɛtsɔ perovskite fã ni tsɔɔ hiɛ lɛ mli 40 μL ni akɛwoɔ UV-ozone-ni akɛtsu nii yɛ SnO2 fã lɛ nɔ lɛ nɔ yɛ 5000 rpm yɛ kɔɔyɔɔ ni yɔɔ jɛmɛ lɛ mli kɛha 25 s. 5 Sɛkɛndii 5 yɛ naagbee be lɛ sɛɛ lɛ, ajie MACl IPA mli nu (4 mg/mL) 50 μL lɛ oya yɛ shishigbɛ nɔ lɛ nɔ akɛ nɔ ni gbeɔ nu lɛ. No sɛɛ lɛ, akɛ sinii ni afee ehee lɛ wo la mli yɛ 150°C mli minitii 20, ni no sɛɛ lɛ akɛwo la mli yɛ 100°C mli minitii 10. Beni ajie perovskite sini lɛ mli fɛ̃i kɛyashɛ ŋwɛi fɛ̃i mli lɛ, akɛ H2C2O4 mli nu (1, 2, 4 mg ni akɛwo 1 mL IPA mli) lɛ wo tsɔne mli yɛ 4000 rpm kɛha 30 s koni ekɛha perovskite lɛ hiɛ afee nɔ ni bɛ hewalɛ. Akɛ spiro-OMeTAD tsofa ko ni asaa kɛtsɔ spiro-OMeTAD 72.3 mg, CB 1 ml, tBP 27 μl kɛ Li-TFSI 17.5 μl (520 mg yɛ acetonitrile 1 ml mli) ni akɛfutu mli lɛ nɔ lɛ shwie sini lɛ nɔ yɛ 4000 rpm mli. Yɛ naagbee lɛ, Au fã ni tsiimɔ ji 100 nm lɛ shwie shi yɛ he ko ni nɔ ko bɛ mli yɛ oyaiyeli ni ji 0.05 nm/s (0~1 nm), 0.1 nm/s (2~15 nm) kɛ 0.5 nm/s (16~100 nm) mli. ).
Akɛ Keithley 2400 mita ni yɔɔ hulutsoo simulator la (SS-X50) shishi lɛ tsu nii kɛsusu SC nitsumɔ ni perovskite hulutsoo be mli tsɔnei lɛ tsuɔ lɛ he yɛ la ni mli wa ni ji 100 mW/cm2 mli, ni akɛ silicon hulutsoo be mli tsɔnei ni ato he gbɛjianɔ lɛ tsu nii kɛkwɛ mli. Kɛji akɛ akɛɛɛɛ gbɛ kroko nɔ lɛ, asusu SP curves lɛ he yɛ glove adeka ni nitrogen eyi mli obɔ lɛ mli yɛ tsu mli latsaa mli (~25°C) yɛ hiɛ kɛ sɛɛ skan gbɛi amli (voltage step 20 mV, sɛɛkuu be 10 ms). Akɛ shadow mask tsu nii koni akɛna he ko ni tsuɔ nii jogbaŋŋ ni ji 0.067 cm2 kɛha PSC ni asusu lɛ. Akɛ PVE300-IVT210 gbɛjianɔtoo (Industrial Vision Technology(s) Pte Ltd) ni kane ni yɔɔ su kome pɛ ni yɔɔ tsɔne lɛ nɔ lɛ tsu nii kɛsusu EQE he yɛ kɔɔyɔɔ ni yɔɔ jɛmɛ lɛ mli. Kɛha tsɔne lɛ shifimɔ lɛ, aka hulutsoo be mli nibii ni akɛwoɔ mli lɛ aka yɛ nitrogen glovebox mli yɛ 100 mW/cm2 hewalɛ ni UV filta bɛ mli. Akɛ PHI nanoTOFII be-kɛ-fãmɔ SIMS tsuɔ nii kɛsusuɔ ToF-SIMS he. Akɛ 4 kV Ar ion tu ni elɛɛmɔ ji 400×400 μm tsu nii kɛna bɔ ni mli kwɔ ha.
Akɛ X-ray fotoelektron ŋwɛi ŋtayaa (XPS) susumɔi tsu nii yɛ Thermo-VG Jeŋ Nilee gbɛjianɔtoo (ESCALAB 250) nɔ kɛtsɔ monochromatized Al Kα (kɛha XPS gbɛ nɔ) nɔ yɛ 5.0 × 10–7 Pa nɔnyɛɛ mli. Akɛ atomik hewalɛ nibii bibii ni akɛkwɛɔ nibii bibii (AFM) (Bruker Dimension FastScan) lɛ susu bɔ ni perovskite sinii lɛ hiɛ yɔɔ ha kɛ bɔ ni amɛhe yɔɔ ŋmɔlɔŋmɔlɔ lɛ he. Afee STEM kɛ HAADF-STEM yɛ FEI Titan Themis STEM lɛ. Akɛ UV-3600Plus (Shimadzu Nitsumɔhe) tsu nii kɛsusu UV-Vis ni ŋmɛɔ la lɛ he. Akɛ ŋwɛi tsɔne ni tsiɔ nii anaa (SCLC) lɛ wo Keithley mita 2400 nɔ. Akɛ FLS 1000 fotoluminescence spectrometer tsu nii kɛsusu fotoluminescence ni yɔɔ shiŋŋ (PL) kɛ fotoluminescence ni akɛtsuɔ nii yɛ be mli (TRPL) ni kɔɔ tsɔne ni hiɛɔ wala be mli fitemɔ he lɛ he. Akɛ Horiba LabRam Raman gbɛjianɔtoo HR Sutsakemɔ tsu nii kɛsusu PL shikpɔŋ he mfoniri he mfonirii lɛ ahe. Akɛ Thermo-Fisher Nicolet NXR 9650 gbɛjianɔtoo tsu nii kɛkwɛ bɔ ni hulutsoo be lɛ tsakeɔ ehaa lɛ nɔ.
Yɛ nitsumɔ nɛɛ mli lɛ, wɔkɛ SSW gbɛ nɔkwɛmɔ gbɛ lɛ tsuɔ nii kɛkaseɔ fã tsakemɔ gbɛ kɛjɛɔ α-fa kɛyaa δ-fa. Yɛ SSW gbɛ nɔ lɛ, hewalɛ ni baanyɛ aba lɛ hiɛ lɛ nyiɛmɔ lɛ ji nɔ ni random soft mode (second derivative) lɛ gbɛtsɔɔmɔ lɛ tsɔɔ, ni no haa anyɛɔ akaseɔ hewalɛ ni baanyɛ aba lɛ he nii fitsofitso kɛ yiŋtoo. Yɛ nitsumɔ nɛɛ mli lɛ, atsuɔ gbɛ he nɔkwɛmɔnɔ he nii yɛ 72-atom supercell nɔ, ni abuaa shishijee/naagbee shihilɛ (IS/FS) enyɔ ni fa fe 100 naa yɛ DFT ŋwɛigbɛ. Kɛtsɔ IS/FS pairwise data set lɛ nɔ lɛ, abaanyɛ atsɔɔ gbɛ ni kɛ shishijee gbɛjianɔtoo lɛ kɛ naagbee gbɛjianɔtoo lɛ tsaa lɛ kɛtsɔ tsakpaa ni yɔɔ atom lɛ teŋ lɛ nɔ, ni no sɛɛ lɛ, akɛ gbɛi enyɔ ni nyiɛɔ variable unit surface lɛ nɔ lɛ tsuɔ nii koni akɛtsɔɔ tsakemɔ shihilɛ gbɛ lɛ jogbaŋŋ. (VK-NƆMƆ). Beni atao tsakemɔ shihilɛ lɛ sɛɛ lɛ, abaanyɛ ana gbɛ ni yɔɔ gbɛtsii nii ni baa shi fe fɛɛ lɛ nɔ kɛtsɔ hewalɛ gbɛtsii nii lɛ ni ato he gbɛjianɔ lɛ nɔ.
Akɛ VASP (version 5.3.5) tsu DFT akɔntaabuu fɛɛ he nii, he ni electron–ion nifeemɔi ni yɔɔ C, N, H, Pb, kɛ I atoms lɛ mli lɛ damɔ shi kɛha ŋwɛi ŋshɔkei ni ajieɔ lɛ kpo (PAW) gbɛjianɔtoo lɛ. Atsɔɔ tsakemɔ tsakpaa nitsumɔ lɛ mli kɛtsɔ ŋwɛi ŋta ni yɔɔ Perdue-Burke-Ernzerhoff mli lɛ nɔ. Akɛ hewalɛ ni ato kɛha kɔɔyɔŋ lɛlɛ mli ŋshɔkei lɛ to 400 eV. Monkhorst-Pack k-gbɛjianɔtoo lɛ dalɛ ji (2 × 2 × 1). Kɛha gbɛjianɔtoi fɛɛ lɛ, lattice kɛ atomic shihilɛi lɛ ji nɔ ni hi jogbaŋŋ kwraa kɛyashi nɔnyɛɛ ni fe fɛɛ lɛ fã lɛ ba shi yɛ 0.1 GPa shishi ni hewalɛ ni fe fɛɛ lɛ fã lɛ ba shi yɛ 0.02 eV/Å shishi. Yɛ ŋwɛi nɔkwɛmɔnɔ lɛ mli lɛ, FAPbI3 hiɛ lɛ yɛ ŋwɛi ŋtayaai 4, shishigbɛ ŋtayaa lɛ yɛ atom ni yɔɔ shiŋŋ ni feɔ FAPbI3 gbɔmɔtso lɛ he mfoniri, ni ŋtayaai etɛ ni yɔɔ ŋwɛi lɛ baanyɛ aya he fɛɛ he yɛ be mli ni atsuɔ nii jogbaŋŋ lɛ. PbC2O4 ŋta lɛ dalɛ ji 1 ML ni eyɛ FAPbI3 I-terminal lɛ nɔ, he ni Pb kɛ 1 I kɛ 4 O kpãa gbee yɛ lɛ.
Kɛji ootao saji babaoo ni kɔɔ bɔ ni ato nikasemɔ lɛ he gbɛjianɔ aha lɛ he lɛ, kwɛmɔ Natural Portfolio Report Abstract ni kɛ niŋmaa nɛɛ yɔɔ tsakpaa lɛ.
Akɛ saji fɛɛ ni ana loo akwɛ mli yɛ nikasemɔ nɛɛ mli lɛ ewo sane ni akala lɛ mli, kɛ agbɛnɛ hu yɛ saji ni fiɔ sɛɛ kɛ saji ni aŋmala ashwie shi lɛ amli. Nibii ni aŋmala ashwie shi ni ajie lɛ kpo yɛ nikasemɔ nɛɛ mli lɛ yɛ https://doi.org/10.6084/m9.figshare.2410016440. Akɛ saji ni jɛ mli ba lɛ eha kɛha niŋmaa nɛɛ.
Green, M. kɛ ekrokomɛi. Hulu mli nibii ni tsuɔ nii jogbaŋŋ lɛ ahe okpɔlɔi (57th ed.). gbɛjianɔtoo lɛ. fotoelektrik. nibii ni akɛtsuɔ nii. aplikashiŋ. 29, 3-15 (2021).
Parker J. kɛ ekrokomɛi. Akɛ alkyl ammonium chlorides ni sɛɛ tsɛɔ tsuɔ nii kɛkwɛɔ perovskite ŋmeii lɛ adalɛ nɔ. Adebɔɔ 616, 724-730 (2023).
Zhao Y. kɛ ekrokomɛi. (PbI2)2RbCl ni tsuuu nii lɛ haa perovskite sinii lɛ yaa hiɛ kɛha hulutsoo be mli nibii ni tsuɔ nii jogbaŋŋ lɛ. Jeŋ nilee 377, 531-534 (2022).
Tan, K. kɛ ekrokomɛi. Akɛ dimethylacridinyl tsofa ni akɛwoɔ mli lɛ tsuɔ nii kɛtsakeɔ hulutsoo be mli nibii. Adebɔɔ, 620, 545-551 (2023).
Han, K. kɛ ekrokomɛi. Formidine ni ji kristalo kome ni ji lead iodide (FAPbI3): nibii ni kɔɔ bɔ ni ato nii ahaa, nibii ni anaa kɛ tsɔne mli nibii ahe. mligbalalɔi. Mat. 28, 2253-2258 (2016).
Massey, S. kɛ ekrokomɛi. Perovskite diŋ lɛ mlihilɛ yɛ FAPbI3 kɛ CsPbI3 mli. AKS Hewalɛ Sanegbaai. 5, afi 1974 kɛyashi afi 1985 (2020).
Bo, JJ, kɛ ekrokomɛi. Perovskite hulutsoo be mli wala yibii ni tsuɔ nii jogbaŋŋ kɛtsɔ tsɔne ni akɛwoɔ mli lɛ nɔkwɛmɔ ni hi jogbaŋŋ nɔ. Adebɔɔ 590, 587-593 (2021).
Saliba M. kɛ ekrokomɛi. Rubidium cations ni akɛwoɔ perovskite hulutsoo be mli lɛ haa fotovoltaik nitsumɔ yaa hiɛ. Jeŋ nilee 354, 206-209 (2016).
Saliba M. kɛ ekrokomɛi. Triple-cation perovskite cesium hulutsoo be mli wala yibii: shifimɔ ni yaa hiɛ, fɔmɔ ekoŋŋ kɛ nitsumɔ ni hi jogbaŋŋ. hewalɛ shihilɛ mli. jeŋ nilee lɛ. 9, afi 1989 kɛyashi afi 1997 (2016).
Cui X. kɛ ekrokomɛi. Nɔyaa ni eba nyɛsɛɛ nɛɛ yɛ FAPbI3 fã ni haa mɔ tsui nyɔɔ emli yɛ perovskite hulutsoo be mli nibii ni tsuɔ nii jogbaŋŋ lɛ amli Sol. RRL 6, 2200497 (2022).
Delagetta S. kɛ ekrokomɛi. Foto-induced fã mligbalamɔ ni yɔɔ halide ni akɛfutuɔ nibii ni wala yɔɔ mli-nibii ni wala bɛ mli ni ji perovskites lɛ mli. Nat. gbaa sane. 8, 200 (2017).
Slotkavage, DJ kɛ ekrokomɛi. La ni haa mɔ mli gbalaa yɛ halide perovskite nibii ni ŋmɛɔ nii amli lɛ amli. AKS Hewalɛ Sanegbaai. 1, 1199-1205 (2016).
Chen, L. kɛ ekrokomɛi. Nɔ ni yɔɔ mli lɛ mli shidaamɔ kɛ mligbɛ bandgap ni ji formamidine ni hiɛ triiodide perovskite kristalo kome. Anjiva. Tsofa. majimaji ateŋ nifeemɔ. Ed. 61. afi 2022 (2022).
Duinsti, EA etc. Nuu bɔ ni methylenediammonium lɛ fiteɔ kɛ egbɛfaŋnɔ yɛ fã ni ji lead triiodide formamidine lɛ mli lɛ shishi. J. Tsofafeemɔ. Bitch. 18, 10275-10284 (2023).
Lu, HZ kɛ ekrokomɛi. Perovskite hulutsoo be mli wala yibii FAPbI3 ni tsuɔ nii jogbaŋŋ ni yɔɔ shiŋŋ. Jeŋ nilee 370, 74 (2020).
Doherty, TAS kɛ ekrokomɛi. Oktahedral halide perovskites ni yɔɔ shiŋŋ lɛ tsiɔ fãi ni yɔɔ he kome ni yɔɔ sui fioo lɛ anaa. Jeŋ nilee 374, afi 1598-1605 (2021).
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Zheng J. kɛ ekrokomɛi. Nibii ni haa mɔ he jɔɔ lɛ ahe nitsumɔ kɛha α-FAPbI3 perovskite hulutsoo be mli wala yibii. Adebɔɔ 592, 381-385 (2021).