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.