Monolithic perovskite/silicon tandem solar cells: combining stability with high performance

Perovskite/silicon tandem is a new high-efficiency photovoltaic platform that converts sunlight into electricity with excellent performance. In few years, this driving factor have pushed the tandem technology already at the entrance of the photovoltaic market. However, to succeed towards their commercialization, the tandems need to secure the stability of the performances, in line with the warranty certificates of commercial crystalline silicon modules. Enhancing the stability while preserving record performances is a challenge that can be addressed with different approaches. In this direction, bifacial tandem solar cells are a potential solution. In this configuration, light is absorbed both at the sun-side and at the rear-side of the device by exploiting the albedo - the scattered and reflected photons from the ground. Thanks to the additional photons arising from the albedo, the bifacial configuration enhances its current above the conventional configuration, resulting in even better performances. The current enhancement is achieved by tailoring the perovskite bandgap, resulting in bromide-free composition. This composition significantly improve the stability of the performances, by suppressing the mechanism of halide segregation. Overall, the bifacial configuration combine together enhanced efficiency and better stability, promising the technology at the utility scale, towards a carbon-sustainable economy.