Pizza Oven Processing of Organohalide Perovskites (POPOP): A Simple, Versatile and Efficient Vapor Deposition Method

Hybrid vapor deposition is one of the most appealing processes for perovskite photovoltaics fabrication, thanks to its versatile nature. By using sequentially different vapor deposition processes tailored to the inorganic and organic perovskite precursors' peculiarities, this type of process gives access to the full potential of vapor deposition. While vapor deposition of metal halides is well understood and mastered, vapor deposition of organohalide species is much more delicate (degradation of vapors, high vapor pressure, setup-specific constraints). Here, a novel close space sublimation system is reported and in-depth insights on the conversion into perovskite of a metal halide template are provided. In this evolution of the process, the substrate coated with metal halide template and the organohalide source are loaded together in a dedicated holder, then transferred into a vacuum chamber on a heating element already at temperature setpoint. The system enables a simple, fast, low-cost, and easy-to-reproduce organohalide vapor deposition process. The formation of the perovskite in situ and identification different conversion regimes are studied. Furthermore, the influence of the chemical environment and chamber design on the process are discussed. Compositional tuning and additive engineering in the process are processed and fabricate proof of concept photovoltaic devices reaching high fill factors of 80% and 17% power conversion efficiency for a bandgap of 1.63 eV.