Lead 2 iodide

Methylammonium iodide (CH₃NH₃I (MAI), 99.99%), methylammonium bromide (CH₃NH₃Br (MABr), 99.99%) and formamidinium iodide (CH(NH₂)₂I (FAI), 99.99%), and formamidinium bromide (CH(NH₂)₂Br (FABr), 99.99%) were purchased from Hangzhou Perov Optoelectronic Technology Co., Ltd. Lead (II) iodide (99.99% metals basis), lead (II) bromide (>98%), cesium bromide (>99%), cesium iodide (>99%), and bathocuproine (>99%) were purchased from Tokyo Chemical Industry Co., Ltd. All other chemicals were purchased from Sigma-Aldrich and used as received.

Indium nitrate hydrate (In(NO₃)₃·xH₂O, 99.999%) powder, N,N-dimethylacetamide (DMAC, 99.5%) were purchased from Sigma-Aldrich. 2-methoxyethanol (2-ME, 99.3%), acetylacetone (AcAc, 99%) and ammonium hydroxide (NH₃·H₂O, 28%) were obtained from Alfa Aesar. Formamidinium iodide (FAI, >98.0%), Methylammonium iodide (MAI, >99.0%), Cesium iodide (CsI, >99.0%), Lead (II) iodide (PbI₂, 99.99%), Methylammonium bromide (MABr, >99.0%) and Lead(II) bromide (PbBr₂, 99.99%) were purchased from Tokyo Chemical Industry Co. Ltd (TCI). Temozolomide (DMSO, 99%), N,N-Dimethylformamide (DMF, 98%) and chlorobenzene (CB, 99.8%) were purchased from J&K Scientific. Dichloromethane (DCM) was obtained from Innochem Science & Technology Co., Ltd. Colorless polyimide (CPI) powder was from Zhejiang OCAs New Materials Co. Ltd. Silicon wafer with 100 nm thick SiO₂ layer was obtained from Silicon Valley Microelectronics, Inc. Isopropyl alcohol (AR, 99.7%), acetone (AR, 99.5%) and hydrochloric acid (HCl; AR, 36–38%) were provided by China National Medicines Co. Ltd. (Shanghai, China). Poly(perfluoroalkyl vinyl ether) (CYTOP) was purchased from Asahi glass company (Japan) and consisted of CTL-809M (solute) and CT-Solv.180 (solvent). Polymethyl methacrylate (PMMA, 495 K A2) was purchased from Kayaku Advanced Materials.

L-phenylalanine methyl ester hydrochloride and tin(IV) chloride dihydrate (SnCl₄·5H₂O, >98.0%) were obtained from FUJIFILM Wako Pure Chemical Corporation, Osaka, Japan. Titanium isopropoxide (TTIP, >97%) and lithium chloride (LiCl, 99.0%) were purchased from KANTO CHEMICAL Co., Inc., Tokyo, Japan.
Dehydrated solvents, N,N-dimethylformamide (DMF, >99.5%), dimethyl sulfoxide (DMSO, 99.0%), 2-propanol (IPA > 99.7%), and acetonitrile (CH₃CN > 99.5%) were supplied from KANTO CHEMICAL Co., Inc., Tokyo, Japan. Ethanol (99.5%) was from Kanto Chemical Co., Inc., Tokyo, Japan. A Milli-Q^® integral water purification system (MERCK Ltd., Tokyo, Japan) was used for obtaining H₂O (resistivity: 18.2 MΩ·cm). All the chemicals were used as purchased for the experiments.
For the fabrication of perovskite solar cells, lead(II) iodide (PbI₂, 99.99%), methylamine hydrobromide (MABr, >98.0%), cesium iodide (CsI, >99.0%), formamidine hydroiodide (FAI, 99.99%), lithium bis(trifluoromethanesulfonly)imide (Li-TFSI, >98.0%), and formamidine hydrobromide (FABr, 99.99%) were obtained from TOKYO CHEMICAL INDUSTRY CO., Ltd., Tokyo, Japan. Spiro-MeOTAD, chlorobenzene (CB, 99.8%), and 4-tert-butylpyridine (TBP, 98%) were from SIGMA-ALDRICH, Co., St. Louis, MO, USA.

Lead(II) iodide (PbI₂; 99.99%, trace metals basis) and lead(II) bromide (PbBr₂; >98.0%) were purchased from Tokyo Chemical Industry (TCI). Methylammonium chloride (MACl; 98%), cesium iodide (CsI; 99.9%, trace metals basis), anhydrous N, N-dimethylformamide (DMF; 99.8% v/v), anhydrous dimethyl sulfoxide (DMSO, 99% v/v), anhydrous chlorobenzene (99.8%), anhydrous ethyl acetate (99.8%), anhydrous ethanol (ethanol; 99.5% v/v), tin(II) chloride dihydrate (SnCl₂·2H₂O; 99.999%), hydrochloric acid (HCl; 37% v/v), 4-tert-butylpyridine (tBP), lithium bis-(trifluoromethanesulfonyl) imide (Li-TFSI), acetonitrile (anhydrous; 99.8%), copper(I) thiocyanate (CuSCN; 99%), and diethyl sulfide 98% were purchased from Sigma Aldrich. Propan-2-ol (AR grade) was purchased from RCI labscan. Formamidinium iodide (FAI; >99.99%), formamidinium bromide (FABr; >99.99%), and methylammonium bromide (MABr; >99.99%), and TEC15 FTO glass plate (2.2 mm thick) were purchased from Greatcell solar. TEC15 ITO glass (1.1 mm thick) was purchased from Luminescence Technology Corp. Tin(IV) oxide (15wt% in H₂O colloidal dispersion) and ferrocene (99%) were purchased from Alfa Aesar. 2,20,7,70-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,90-spirobifluorene (spiro-OMeTAD) was purchased from Feiming chemical. Alconox detergent powder was purchased from Alconox. Carbon paste (Jelcon CH-8) was purchased from Jujo chemical.

Titanium tetraisoproxide (TTIP, >97.0%), N,N-dimethylformamide (DMF, dehydrated, >99.5%), dimethyl sulfoxide (DMSO, dehydrated, 99.0%), 2-Propanol (IPA, dehydrated, >99.7%), and acetonitrile (dehydrated, >99.5%) were purchased from Kanto Chemical Co., Inc. (Portland, OR, USA). Spiro-MeOTAD, chlorobenzene (CB, anhydrous, 99.8%), Terpineol (anhydrous), and 4-tert-butylpyridine (TBP, 98%) were obtained from Sigma-Aldrich, Co. (St, Louis, MI, USA). Methylamine hydrobromide (MABr, >98.0%), Cesium iodide (CsI, >99.0%), Formamidine hydroiodide (FAI, 99.99%), Lead(II) iodide (PbI2, 99.99%), Lithium bis(trifluoromethanesulfonly)imide (Li-TFSI, >98.0%), and Formamidine hydrobromide (FABr, 99.99%) were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). Polyethylene glycol 400 (PEG400) and Tin(II) chloride dihydrate (SnCl₂·2H₂O, >97.0%) were from FUJIFILM Wako Pure Chemical Corporation, Richmond, VA, USA. All chemicals were used as purchased.

Lead (II) iodide (PbI₂, 99.99 %, trace metals basis) and methylamine hydroiodide (CH₃NH₃I, Low water content) were purchased from Tokyo Chemical Industry (TCI) and used without further purification. A 1.5 m perovskite precursor solution was prepared by dissolving PbI₂ and CH₃NH₃I at a molar ratio of 1 : 1 in N,N‐dimethylformamide and dimethyl sulfoxide mixed solution (9 : 1.1 volume ratio) at 60 °C overnight. Titanium (IV) isopropoxide (TTIP), 3‐phenyl‐1‐propylamine (PPA), bis(diphenylphosphino)methane (DPPM), and bathocuproine (BCP, 96 %) and were purchased from Sigma‐Aldrich. The BCP solution was prepared by dissolving BCP in methanol with a concentration of 0.05 wt %. The poly(bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine) (PTAA) and poly(9,9‐bis(3′‐(N,N‐dimethyl)‐N‐ethylammonium‐propyl‐2,7‐fluorene)‐alt‐2,7‐(9,9‐dioctylfluorene))dibromide (PFN−Br) were purchased from 1‐Material and dissolved in toluene (anhydrous, 99.8 %) and methanol (anhydrous, 99.8 %) at a concentration of 2 mg/mL and 0.5 mg/mL, respectively. All other materials and solvents were purchased from Sigma‐Aldrich and used without further purification unless otherwise stated.

Lead (II) iodide (PbI₂; 99.99%) and lead (II) bromide (PbBr₂; >98.0%) were purchased from TCI America. Formamidinium iodide (FAI;) and methylammonium bromide (MABr;) were purchased from GreatCell Solar Materials. Bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI) was purchased from Alfa Aesar. Cesium iodide (CsI; 99.999%) and 4-tert-butylpyridine (tBP; 96%) was purchased from Sigma-Aldrich. 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamino)-9,9′-spirobifluorene (spiro-OMeTAD; ≥99.5%) was purchased from Lumtec, SnO₂ colloidal dispersion was obtained from Alfa Aesar and diluted to 1.5% in DI water before use. Poly(triaryl amine) (PTAA; 5–20 kDa) was obtained from Solaris Chem, and poly(9,9-bis(3’-(N,N-dimethyl)-N-ethylammoinium-propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene))dibromide (PFN-Br) was purchased from 1-Material. All the solvents (dimethylformamide (DMF), dimethylsulfoxide (DMSO), chlorobenzene (CB), toluene, methanol) were obtained from Sigma-Aldrich.