Solar perovskite thin films with enhanced mechanical, thermal, UV, and moisture stability via vacuum-assisted deposition

Perovskites are promising solution processible materials widely used for solar cell application. We developed a vacuum-assisted deposition (VAD), which allowed spin-coating process under different vacuum conditions. Via two-step deposition for perovskite solution, VAD affects evaporation rate during deposition and perovskite formation. VAD improved all key properties necessary for optoelectronics like morphology, UV–visible absorption, and crystallinity along with UV, thermal, and moisture stability. Moreover, perovskite films became harder with VAD, paving the way for high mechanical stability. VAD opened a new door for high stability, dense perovskite films and could be adapted for various perovskite compositions for optoelectronic application.