|Gujar, T.P.; Thelakkat, M.: Highly Reproducible and Efficient Perovskite Solar Cells with Extraordinary Stability from Robust CH3NH3PbI3: Towards Large-Area Devices, Energy Technology, 4(3), 449–457 (2016) -- DOI: 10.1002/ente.201500421|
Organic–inorganic hybrid solar cells based on air-stable CH3NH3PbI3 perovskites are reported. The perovskite layer was synthesized by CH3NH3I (methylammonium iodide, MAI) vapor-assisted growth on a PbI2 layer. This process is optimized to achieve uniform, pore-free, compact, and highly stable crystalline perovskite layers. The extraordinary stability of this pristine perovskite layer for about 3 months in air was compared with films obtained by other crystallization methods using X-ray diffraction (XRD) studies. The effect of the perovskite layer thickness on the photo-conversion efficiency (PCE) and external quantum efficiency are evaluated. The solar cell optimization reveals that the 370 nm thick perovskite layer delivers highly reproducible devices with a PCE value of 14.8 % (average 13.4 %) and negligible parameter fluctuation as well as high stability (of more than one month) with negligible loss. Additionally, we demonstrate that this MAI vapor-assisted method is suitable to fabricate devices having an area of 1.05 cm2 and device efficiency of 8.7 %.