Highly Efficient and Stable Semi‐Transparent p‐i‐n Planar Perovskite Solar Cells by Atmospheric Pressure Spatial Atomic Layer Deposited ZnO

The replacement of the conventional top metal contact with a semi‐transparent conducting electrode such as sputtered indium‐tin oxide (ITO) is strictly required to adopt the perovskite solar cell (PSC) in hybrid tandem photovoltaic applications. In order to prevent sputtering damages on the perovskite absorber and the organic materials adopted in p‐i‐n planar architecture, an atmospheric pressure spatial atomic layer deposited (s‐ALD) ZnO buffer layer has been included. The use of a 45 nm thick s‐ALD layer enables the fabrication of a PSC with a power conversion efficiency (PCE) of 14.7%, with a similar PCE when illuminated from the ITO/s‐ALD ZnO side. When adopted in a four terminal configuration with a c‐Si solar cell (PCE of 18.6%), a 2.5% absolute PCE gain is observed with respect to the stand alone c‐Si. Finally, the semi‐transparent PSC shows an excellent shelf life, and only −4% degradation on the tracked maximum power point when encapsulated and aged at 65 °C in an inert atmosphere after 1500 h.