Performance enhancement of 2D tin-halide perovskite transistors via molecule-assisted grain boundary passivation and hole doping

Abstract

Tin (Sn2+)-based halide perovskites have garnered considerable interest for potential applications in field-effect transistors, owing to their low-cost solution processing capability and favorable hole transport properties. However, the polycrystalline nature of halide perovskite films necessitates efficient grain boundary passivation for reliable and stable device operation. Additionally, as a p-type semiconductor, controllable hole-doping is desired for modulating electrical properties. In this study, we demonstrate the dual functionality of doping the small molecule tetrafluoro-tetracyanoquinodimethane (F4TCNQ) into (C6H5C2H4NH3)2SnI4 (abbreviated as (PEA)2SnI4) through a cost-effective solution process. This doping introduces F4TCNQ as both a grain boundary passivator and a charge transfer p-dopant, resulting in effective improvements in transistor performance with a 6-fold enhancement in mobility, a substantial reduction in hysteresis, an enhanced current ratio, and improved stabilities.