CsPbIBr2-Based Bifacial Semitransparent Solar Cells for All-Day Applications

Among all-inorganic perovskites, CsPbIBr 2 has become a potential candidate in semitransparent perovskite solar cells (ST-PSCs) due to its excellent thermal stability and suitable bandgap. Herein, by optimizing the ambient temperature in an N 2 -filled glovebox, the growth process of CsPbIBr 2 crystals is regulated to avoid the generation of pinholes and improve the photoelectric conversion capacity of perovskite cells. When the ambient temperature is around 25 °C, the champion power conversion efficiency (PCE) of 10.82% with opaque n–i–p structure is achieved. Based on MoO x /Ag/MoO x (20/12/20 nm) multilayer top electrode, the ST-PSC device achieves a maximum PCE of 7.06% at the fluorine-doped tin oxide side under the simulated 1 sun illumination condition and a PCE of 23.96% at MoO x /Ag/MoO x electrode side under the intensity of 1000 lux (≈350 μW cm −2 ) provided by a white light-emitting diode lamp, along with an average visible transmittance of 29.25%. The resulting perovskite solar cell is the first bifacial inorganic ST-PSC that could be used under both sunlight and indoor light, which is an important step toward all-day power generation of inorganic ST-PSCs and building-integrated photovoltaics.