Cesium bromide

Rhenium, sulfur, bromine, cesium bromide, 1H-pyrazole-1-carboxamidine hydrochloride (99%), lead(ii) iodide (99.999% trace metals basis, perovskite grade), methylammonium iodide (MAI) (99%, anhydrous), and N,N-dimethylformamide (DMF) (anhydrous, 99.8%) were purchased from Sigma Aldrich and used without additional purification. Polymeric precursor Re₆S₈Br₂ was prepared via high-temperature solid-state synthesis from elemental Re and S powders and Br₂ liquid.

Lead(II) bromide (PbBr₂, 99.999% trace metals basis); cesium bromide (CsBr, 99.999% trace metals basis); lead(II) chloride (PbCl₂, 99.999% trace metals basis); cesium chloride (CsCl, 99.999% trace metals basis) and polymethyl methacrylate (Mw = 120,000 g/mol) (PMMA) were purchased from Sigma-Aldrich (Saint Louis, MO, USA). All chemicals were used as received, without further purification.

Lead bromide (PbBr₂, 99.0%, AR chemicals, Delhi, India), cesium bromide (CsBr, 99.9%, Sigma-Aldrich, Darmstadt, Germany), oleic acid (OA, 98%, Sigma-Aldrich, Darmstadt, Germany), oleylamine (OAm, technical grade 70%, Sigma-Aldrich, Darmstadt, Germany), olive oil (OO, Nice, Kochi, India), hexane (≥97.5%, Sigma-Aldrich, Darmstadt, Germany), N,N-dimethylformamide (DMF, 99.5%, AR chemicals, Delhi, India), and toluene (≥99.5%, AR chemicals, Delhi, India) were used in this experiment. All chemicals were used without further purification.

Cesium bromide (CsBr, 99.999%), lead bromide (PbBr₂, 99.999%), oleic acid (OA, 90%), dimethyl sulfoxide (DMSO, 99.5%), chlorobenzene (CB, 99.5%), and polyethyleneimine (PEI) were obtained from Sigma-Aldrich. Oleylamine (OLA, 80-90%), methyl acetate (99%), and N-butanol (99.8%) were obtained from Aladdin. Hydrobromic acid (40 wt% in H₂O) was purchased from Tianjin Chemical Industry. 4-Dodecylbenzene sulfonic acid (DBSA, 95%) was purchased from Shanghai Acmec Biochemical Co., Ltd. Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), poly(4-butylphenyl-diphenyl-amine) (Poly-TPD), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), and 2,4,6-Tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (POT2T) were purchased from Xi’an Polymer Light Technology Corp. Hexane, ethanol, dichloromethane, isopropyl alcohol, toluene, and acetone were obtained from Sinopharm Chemical Reagent Co., Ltd.

Detailed synthesis information of methylammonium iodide (MAI) and titanium dioxide (TiO₂) can be found in the previous work.^[52] Lead (II) iodide (PbI₂, 99.99%) and polyTPD was purchased from Xi'an Polymer Light Technology in China. Cesium bromide (CsBr, 99.99%), N,N‐Dimethylformamide (DMF, anhydrous, 99.8%), Dimethyl sulfoxide (DMSO, anhydrous, 99.9%) and were purchased from Sigma‐Aldrich. Zinc acetate (Zn(CH₃COO)₂·2H₂O, 99.99%) was purchased from Aladdin. The tin(IV) dioxide (SnO₂, 15% in H₂O) was obtained from Alfa Aesar. High transmittance ITO (resistance ≈15 Ω sq⁻¹, maximum transmittance ≈94% at ≈550 nm, size of 20 × 15 × 0.7 mm³) was purchased from You Xuan Ltd.