2D Sn halide perovskite transistors with interface-enhancing organic molecules via side group modulation

Abstract

Tin (Sn) halide perovskites have emerged as promising lead-free candidates for thin-film transistor (TFT) channels due to their low effective mass and reduced carrier scattering. However, their inherent instability and susceptibility to oxidation-which generates defects and degrades film quality-have limited their practical application. In this study, we demonstrate that molecular interlayers with defect-passivating functional groups improve film quality and reduce oxidation in Sn halide perovskites. Moreover, by modulating their dipole moments, these interlayers lower the energy barrier between the perovskite and the source/drain contacts, facilitating charge transport. Consequently, an interface-modified p-channel PEA2SnI4 TFT achieves exceptional performance, with a field-effect mobility of 14.89 cmVs, an on/off ratio of 9.87 x 106, reduced hysteresis, and outstanding reproducibility and operational stability-attributes essential for low-energy-consumption, CMOSlike electronics.