Efficient Semitransparent Perovskite Solar Cells Based on Thin Compact Vacuum Deposited CH3NH3PbI3 Films

Abstract Lead halide perovskite materials are promising candidates for the application of semitransparent solar cells due to their bandgap tunability and high device efficiencies. The high absorption coefficient of these materials, however, makes it difficult to attain high average visible transmittance values without compromising the power conversion efficiencies (PCEs). In this work, a co‐evaporation process is employed to fabricate thin (50 and 100 nm) methylammonium lead iodide (MAPI) perovskite films and integrate them in semitransparent perovskite solar cells (ST‐PSCs). Due to the compact nature of the thin MAPI films, the resultant fully vacuum and room temperature‐processed devices demonstrate high fill factor values approaching 80% and open‐circuit voltage values close to 1100 mV. As a result of this, the ST‐PSCs exhibit PCE's as high as 9% with a photopic average visible transmittance of the full device of 23%.