Preparation Technuques for Perovskite Single Crystal Films: From Nucleation to Growth

Thickness‐controllable perovskite single crystal films exhibit tremendous potential for various optoelectronic applications due to their capacity to leverage the relationship between diffusion length and absorption depth. However, the fabrication processes have suffered from difficulties in large‐area production and poor quality with abundant surface defects. While post‐treatments, such as passivation and polishing, can provide partial improvement in surface quality, the fundamental solution lies in the direct growth of high‐quality single crystal films. In this work, we firstly summarize the basic principles of nucleation and growth phenomenon of crystalline materials. Advanced growth methods of perovskite single crystal films, including solution‐based, vapor phase epitaxial growth, and top‐down method, are discussed, highlighting their respective advantages and limitations. Finally, we also present future directions and the challenges that lie ahead in perovskite single crystal films.