Thermal Evaporation for Halide Perovskite Optoelectronics: Fundamentals, Progress, and Outlook

Abstract Metal halide perovskites have rapidly advanced the field of optoelectronic devices, especially for photovoltaic (PV) and light‐emitting diode (LED) fields with efficiencies comparable to those well‐established technologies. However, most of the reported perovskite devices are fabricated using lab‐scale solution‐processing methods. The thermal evaporation (TE) method, a mature technique widely used in the semiconductor industry, could be a promising alternative technology for large‐area and scale‐up fabrication. Moreover, the TE method is free of toxic solvent, enables easy control of film thickness, and is compatible with existing industry. This review first presents the fundamentals of the TE method, with an emphasis on the growth mechanism of perovskite films. This is followed by the progress of thermally evaporated perovskite‐based optoelectronic devices, especially solar cells and light‐emitting diodes. Last, the device‐oriented design principles via TE technology are summarized and future development opportunities are overviewed.