Influence of A-Site Cation Composition on the Electronic Properties of Halide Tin Perovskites

Tin halide perovskites are interesting as a potentialreplacementfor lead-based perovskites in various device technologies. However,their charge transport properties have received limited attentioncompared to those of their lead-based counterparts. In particular,the effect of the A-site cation on the electronic properties of tinperovskites warrants further attention to design efficient materialsystems for various applications beyond photovoltaics. In this study,we explore the relationship between the A-site composition and electronicproperties in tin perovskites (ASnI(3)) by leveraging thecomposition tunability of halide perovskites. We investigate the effectof prototypical A-site cations such as formamidinium (FA), methylammonium(MA), and cesium (Cs) and their binary combinations on structure,morphology, and electronic properties of ASnI(3). Our findingsreveal that the MA-Cs combination offers the highest electricalconductivity owing to simultaneously enhanced mobility and carrierdensity compared to single-cation compositions based on MA and Csresulting in a thermoelectric power factor of & SIM;162 & mu;Wm(-1) K-2. The library of propertiesgenerated for Sn perovskites in this work will be valuable for theirfurther development as an electronic material.