Crystallization Control in Thermally Evaporated Perovskite Solar Cells and Light-Emitting Diodes

Metal halide perovskites with exceptional optoelectronic properties have emerged as ideal candidates for next-generation photovoltaic and display technologies. While solution-processed devices are nearing their theoretical efficiency limits, their scalability and stability remain challenging. Thermal evaporation has gained significant attention for fabricating perovskite solar cells (PSCs) and light-emitting diodes (PeLEDs), owing to its advantages in scalability and film uniformity. Recent years have witnessed rapid performance improvements in thermally evaporated devices, approaching those made by solution methods. The critical issue lies in controlling crystallization dynamics to achieve high-quality perovskite films. This perspective reviews the crystallization mechanisms and regulation strategies pertinent to thermally evaporated perovskites. We highlight two mainstream deposition approaches, sequential evaporation and coevaporation, discussing the film formation mechanism and the key deposition parameters on film crystallization. Recent advances in device performance are summarized, and the persistent challenges are outlined to guide future development and accelerate the commercialization of this promising technology.