Bifacial semitransparent inverted planar structured perovskite solar cells (PSCs) based on Cs0.05FA0.3MA0.7PbI2.51Br0.54 using an Ag thin film electrode and V2O5 optical coupling layer are investigated theoretically and experimentally. It is shown that the introduction of the cesium (Cs) ions in the perovskite could obviously improve the device performance and stability. When only the bare Ag film electrode is used, the PSCs show a bifacial performance with the power conversion efficiency (PCE) of 14.62% illuminated from the indium tin oxide (ITO) side and 5.45% from the Ag film side. By introducing a V2O5 optical coupling layer, the PCE is enhanced to 8.91% illuminated from the Ag film side, which is 63% improvement compared with the bare Ag film electrode, whereas the PCE illuminated from the ITO side remains almost unchanged. Moreover, when a back-reflector is employed, the PCE of device could be further improved to 15.39% by illumination from the ITO side and 12.44% by illumination from the Ag side. The devices also show superior semitransparent properties and exhibit negligible photocurrent hysteresis, irrespective of the side from which the light is illuminated. In short, the Ag/V2O5 double layer is a promising semitransparent electrode due to its low cost and simple preparation process, which also point to a new direction for the bifacial PSCs and tandem solar cells.
Keywords: Ag/V2O5; bifacial; perovskite solar cells; semitransparent; stability.