Li bis trifluoromethanesulfonyl imide

Zinc oxide dispersion,
tin chloride (SnCl₂·2H₂O) dehydrate, Al₂O₃ (aluminum oxide) NPs with <50 nm particle
size, magnesium acetate tetrahydrate [(CH₃COO)2Mg·4H₂O], lead(II) bromide (PbBr₂), cesium iodide (CsI), tert-butylpyridine (TBP), Li bis(trifluoromethanesulfonyl)imide
(Li-TFSI), potassium hydroxide solution (KOH), and solvents dimethyl
sulfoxide (DMSO anhydrous, ≥99.9%), N,N-dimethylformamide (DMF anhydrous, 99.8%), diethyl ether
(99.0%), ethanol (99.8%), and 2-propanol anhydrous 99.5% were purchased
from Sigma-Aldrich. Tin(IV) oxide 15% in H₂O colloidal
dispersion and 1-benzyl-3-methylimidazolium chloride (IL1) were purchased
from Alpha Aesar. 1-Butyl-3-methylimidazolium tetrafluoroborate (IL2)
was purchased from Acros Organics. Lead(II) iodide (PbI₂) (99.99%, trace metal basis) was purchased from TCI Deutschland
GmbH. Formamidinium iodide (FAI) methylammonium bromide (MABr), and
methylammonium iodide (MAI) were purchased from GreatCell Solar. 18NR-T
titania paste and cobalt salt (III) FK209 TFSI (98%) were purchased
from Dyesol Limited. 2,2′,7,7′-Tetrakis-(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene
(spiro-OMeTAD) (≥99.8%) was purchased from Borun New Material
Technology Co., Ltd.

All chemicals and materials were used as received, without further purification. Patterned ITO glass (10 Ω/sq) substrates were purchased from Freemteck (Seoul, Republic of Korea). Lead iodide (PbI₂, 99.999% trace metal basis) was received from TCI (Tokyo, Japan). Methylammonium iodide (MAI, crystal) and 2,2′,7,7′-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (Spiro-OMeTAD, 99%) were purchased from NCT Inc. (Seoul, Republic of Korea). Tin (IV) oxide (SnO₂, 15% in H₂O colloidal dispersion) was obtained from Alfa Aesar (Seoul, Republic of Korea). The chemicals, including hexadecanethiol (HDT), 3-aminopropyltriethoxysilane (APTES, 99.999%), methylamine hydrochloride (MACl, 98%), Li-bis(trifluoromethanesulfonyl)imide (Li-salt, 99.95%), dimethylsulfoxide (DMSO, 99.8%), N,N-dimethylformamide (DMF, 99.8%), chlorobenzene (anhydrous, 99.8%), 4-tert-butyl pyridine (TBP, 98%), acetonitrile (99.8%), 2-propanol, acetone, and ethanol were purchased from Sigma–Aldrich (Seoul, Republic of Korea).