The Polymer Society of Korea

Abstract

Tin halide perovskites(THPs) have attracted considerable attention as p-type transistor channel materials due to their low toxicity, intrinsic p-type characteristics.1 However, the poor solubility of SnI2 in organic solvents and its Lewis acidity lead to uncontrolled crystallization, limiting film quality and device performance.2,3 Here, we introduced Lewis base additives, thiourea and dimethylthiourea, to regulate the nucleation and crystal growth of THPs. The additives promoted the formation of larger, more uniform colloidal clusters in the precursor, enabling accelerated and homogeneous nucleation. Moreover, Lewis adduct interactions effectively controlled crystal growth, resulting in compact films with enhanced crystallinity and reduced defect density. As a result, THP transistors exhibit improved performance, with the μ_FE increasing from 62.3 to 76.2 cm2V-1s-1 and the IOn/Off improving from 8.7 × 107 to 4.4 × 108 , along with enhanced operational stability.