Extending the Continuous Operating Lifetime of Perovskite Solar Cells with a Molybdenum Disulfide Hole Extraction Interlayer

Solution processed organic-inorganic lead halide perovskite solar cells (PSCs) are considered as one of the most promising photovoltaic technologies due to the coupling of high performance and low manufacturing cost. However, a key challenge of this technology is their lack of ambient stability over prolonged solar irradiation under continuous operating conditions. Few studies (only in inert atmosphere) already approached the industrial standards. Here, we show how the introduction of MoS2 flakes as a hole transport interlayer in inverted planar PSCs results in a power conversion efficiency (PCE) of ~17%, overcoming the one of the standard reference devices. Furthermore, this approach allows the realization of ultra-stable PSCs, stressed in ambient conditions and working at continuous maximum power point tracking. In particular, the photovoltaic performances of the proposed PSCs represent the current state-of-the-art in terms of lifetime, preserving almost 80% of their initial performance after 568 hours of the continuous stress test, thus approaching the industrial stability standards. Moreover, we further demonstrate the feasibility of our approach by fabricating large area PSCs (0.5 cm2 active area) with MoS2 as the interlayer. These large area PSCs show improved performance (i.e., PCE=13.17%) when compared with the standard devices (PCE=10.64%).