Wide bandgap halide perovskite absorbers for semi-transparent photovoltaics: From theoretical design to modules

The interest in Building Integrated Photovoltaic (BIPV) is growing worldwide. A pivotal role in the development of these technologies can be played by semi-transparent perovskite solar cells (ST-PSCs), thanks to their excellent potential in terms of both Average Visible Transmittance (AVT) and color neutrality. Here, we demonstrate that MAPb(Br1−xClx)3 wide band gap perovskite thin films allow to fabricate efficient and semi-transparent solar cells and modules. To this purpose, electro-optical simulations were employed to optimize the device stack by considering the transmitted/reflected light at each interface between the constituent layers, the composition and the thickness of the perovskite absorber and the impact of the transparent top contact. By combining theoretical and experimental results, we show that the optimal perovskite composition corresponds to a chloride molar ratio equal to 0.13, resulting in a champion device efficiency of 6.3 %, Average Visible Transmittance of 69.4 % and Light Utilization Efficiency of 4.37 %. Furthermore, semi-transparent perovskite mini-modules with a stabilized efficiency of 5.45 % and AVT of 59.4 % with an aperture area of 53.6 cm2 were fabricated defining a new state-of-art for semi-transparent modules. We thus demonstrated efficient and highly semi-transparent perovskite solar modules for the development of PV windows, paving the way for their future integration in architectural components.