In-situ observation of moisture-induced degradation of perovskite solar cells using laser-beam induced current

Solar cells based on organic-inorganic metal halide perovskites have been the focus of photovoltaic research over the past few years due to high power conversion efficiencies up to 22.1% and inexpensive manufacturing costs. However, commercialization of perovskite PV technology is hindered by lack of long-term stability. To elucidate the degradation mechanisms in the state of the art perovskite solar cells, we used laser beam induced current (LBIC) mapping to spatially resolve the device degradation during aging under high humidity conditions. We confirm that perovskites are prone to decomposition in the presence of water. By varying the absorber and hole-transport materials of the devices, we are able to compare performance and identify the water ingress and degradation mechanisms. These results provide insight into the design of materials and device architectures that may improve operational stability of perovskite solar cells.