Tin 4 oxide sno2

Tin (IV) oxide (SnO₂, 15% in H₂O colloidal dispersion) was purchased
from Alfa Aesar. The MAPbI₃ perovskite precursors, lead
(II) iodide (PbI₂, 99%) and methylene ammonium iodide (MAI,
97%), were purchased from TCI. N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis
(4-methoxyphenyl)-9,9′- spirobi[9H-fluorene]-2,2′,7,7′
tetramine (spiro-OMeTAD, 99%) were all purchased from Borun Chem.
Exfoliated GO, dodecyl amine (DDA, ≥ 99%), glycine (≥99%),
anhydrous DMF (99.8%), anhydrous DMSO (≥ 99.5%), anhydrous
ethyl acetate (99.8%), anhydrous acetonitrile (99.8%), anhydrous toluene
(99.8%), anhydrous chlorobenzene (99.8%), and anhydrous hexane (95%)
were purchased from Sigma-Aldrich Company. All the chemicals and reagents
are directly used without any further purification.

Indium tin oxide substrates
(ITO), methylammonium iodide (MAI, 98%), and 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene
(Spiro-MeOTAD, 99%) were purchased from Ossila. Isopropyl alcohol
(IPA, 99.7%), anhydrous dimethylformamide (DMF, 99.8%), dimethyl sulfoxide
(DMSO, 99.8%), acetonitrile (99.8%), chlorobenzene (99.9%), 4-tert-butylpyridine (4-tBP, 96%), lithium
bis(trifluoromethanesulfonyl)imide (LiTFSI, 99.95%), tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)-tris(bis(trifluoromethylsulfonyl)imide)
(FK209, 98%), and pHEMA were purchased from Sigma-Aldrich. Tin (IV)
oxide (SnO₂), Hellmanex III detergent, and lead iodide
(PbI₂) were purchased from Alfa Aesar.