Temperature Field-Driven Directional Space-Confined Crystallization of Perovskite Melt Toward High-Performance Optoelectronic Devices.

The development of optoelectronic devices relies heavily on the advancement of semiconductor materials and microfabrication technologies. Notably, metal halide perovskites with superior optoelectronic properties show great prospects for optical sensing technology. However, the current processing techniques of perovskite materials are mainly solution methods and vapor-phase methods, facing toxic solvents and material waste, which are harmful to the natural environment and human health. Herein, we originally developed the temperature field-driven directional space-confined melt crystallization strategy, which perfectly solved the problems of toxic solvent and material waste, yielding highly crystalline, purely oriented 2D perovskite single-crystal films. Long-range-oriented single-crystal films with fewer crystal domains and defects ensure that optical synaptic devices possess image encryption and high-fidelity polarization imaging capabilities. Furthermore, the melt processing technique enables the fabrication of high-quality 2D-3D perovskite heterojunctions, which notably improve the photodetector performance of 2D perovskite. This pioneering work provides a new strategy and opportunity for the environmentally friendly, high-throughput integration of perovskite optoelectronic devices.