Solution-Free Growth of CsPbBr₃ Perovskite Films Using a Fast and Scalable Close Space Sublimation Method

The all-inorganic metal halide perovskite CsPbBr₃ is a well-known semiconductor which attracts attention from many researchers in the field of optoelectronics. Although CsPbBr₃ in the form of single crystals offers the best charge transport properties, their high cost of fabrication makes them less suitable for large-scale applications. Polycrystalline films, on the other hand, can fill this market gap, and numerous solution- and vapor-based techniques exist to produce them. However, no superior solution has been found yet, and we propose the less explored close space sublimation (CSS), a fast and scalable physical vapor deposition technique, as a viable processing technique for manufacturing CsPbBr₃ films. We show the fabrication of high-quality single-phase CsPbBr₃ films with homogeneous film thicknesses over an area of 3.14 cm². By optimizing the deposition temperature, a growth rate of 10 μm/min can be reached with a material utilization of up to 98%. In addition, the necessary CsPbBr₃ source material is synthesized via ball milling; hence, the whole process is solvent-free. This work aims at rationalizing the CSS process and offering a comprehensive study of the impact of the deposition conditions on the growth of CsPbBr₃.