(TEA,
98%), lead(II) iodide (PbI2, 99.999%, metals basis), isopropyl
alcohol, formamidinium iodide (FAI), methyl ammonium iodide (MAI,
99.9%), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), hydroiodic
acid (HI), tin(IV) oxide (SnO2), titanium diisopropoxide
bis(acetylacetonate), toluene, anhydrous ethanol, chlorobenzene, acetonitrile,
bis(trifluoromethane)sulfonamide lithium salt (Li-TFSI), ethanol,
4-tert-butylpyridine (TBP), tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(III)
tris(bis(trifluoromethyl sulfonyl)imide) (FK209), 1-butanol, and 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene
(Spiro-OMeTAD) were purchased from Sigma-Aldrich. All the materials
were utilized without further purification.