Vapor deposition of organic-inorganic hybrid perovskite thin-films for photovoltaic applications

In this work, we developed CH₃NH₃PbI₃ perovskite films using sequential vapor deposition technique for photovoltaic applications. For thin PbI₂ films vacuum-deposited on different substrates (e. g. Si, PEDOT/PSS/ITO/ glass), the complete conversion to perovskite on exposure to the CH₃NH₃I vapor was confirmed based on X-ray diffraction data. For perovskite films prepared under these vapor deposition conditions, planar heterojunction solar cells were fabricated using PEDOT:PSS and PCBM as the hole and electron transport layer, respectively (glass/ITO/ PEDOT:PSS/CH₃NH₃PbI₃/PCBM/Ag). Under simulated one sun illumination, a high open-circuit voltage of 970 mV with an average efficiency of 4.5% was obtained. While the efficiency of the device with sequential vapor deposited perovskite films needs to be further improved through process optimization, we demonstrated that sequential vapor deposition has a potential to produce high-quality perovskite absorbers for efficient planar heterojunction solar cells.