Record high performance of perovskite/crystalline silicon four-terminal tandem solar cells

Perovskite and crystalline silicon (c-Si) with complementary absorption spectra are connected in a 4-terminal-tandem configuration for efficient utilization of the photons from the complete solar spectrum. A highly transparent electrode with low resistivity is developed by the deposition of molybdenum trioxide (MoO 3 )/Gold (Au)/ molybdenum trioxide (MoO 3 ) multilayer. The thickness of constituent layer of the electrode is carefully controlled to achieve the highest light transmissivity to enhance the absorption of the bottom cell. Perovskite films with low density of bandgap states are obtained by oxygen postdeposition treatment. A record power conversion efficiency (PCE) of 23.6% for tandem device is achieved comparing to 18.1% and 19.1% of transparent perovskite solar cell and c-Si solar cell operated individually.