Antisolvent-Free Crystallization-Directed Two-Dimensional/Three-Dimensional Tin Perovskites for Ambient-Tolerant Electronics

Abstract

Tin (Sn2+) halide perovskites offer a promising lead-free semiconductor platform, yet their practical application is hindered by severe ambient instability. Here, we regulate the early-stage oxygen response of mixed-dimensional Sn2+ perovskites through crystallization pathway engineering without introducing additional stabilizing molecules. Removing antisolvent quenching enables gradual solvent evaporation and cation redistribution, leading to a vertically organized structure with a two-dimensional (2D)-rich surface region and a three-dimensional (3D) FASnI3 transport framework. This architecture balances environmental tolerance and charge transport, where low-dimensional regions contribute to oxygen regulation while the 3D framework maintains efficient hole conduction. Field-effect measurements reveal reversible oxygen-induced conductivity enhancement, suggesting weak oxygen adsorption dominates the initial response. Polymer/oxide encapsulation further improves air stability, and integration with oxide n-channel transistors demonstrates the potential of this approach for complementary thin-film electronics.