Substrate-Independent and Antisolvent-Free Fabrication Method for Tin Perovskite Films via Imidazole-Complexed Intermediates

The fabrication of metal halide perovskite thin films,
particularly
those containing Sn, relies heavily on the use of antisolvents. Film
quality is strongly influenced by factors such as the choice of antisolvent,
the primary precursor solvent, perovskite composition, and the size
and wettability of the substrates. This complexity makes process optimization
challenging and impedes the development of efficient tin perovskite
solar cells (PSCs). In this work, we present a vacuum-quenching with
crystal growth regulator (V-CGR) method, an antisolvent- and dimethyl
sulfoxide (DMSO)-free, vacuum-assisted fabrication process for tin
perovskite films whereby crystal growth could be regulated through
the formation of intermediate films containing an amorphous [SnI2–(1-vinylimidazole)] complex. The V-CGR method is compatible
with diverse perovskite compositions and substrates, enabling the
formation of uniform tin perovskite films up to 7.5 × 7.5 cm2 and allowing device fabrication on hydrophobic hole-transporting
monolayers such as MeO-2PACz and 2PACz.