Application of Cesium Carbonate Modified Electron Transport Layer to Enhance Performance of Perovskite Solar Cells

Titanium dioxide (TiO 2 ) is the most commonly used material for the electron transport layer in perovskite solar cells (PSC), but its material defects have affected the development of perovskite solar cells. In this study, cesium carbonate (Cs 2 CO 3 ) was used to modify the electron transport layer to make it have better electronic conductivity. The structure of the modified perovskite solar cell is FTO/Compact TiO 2 /mesoporous TiO 2 / Cs 2 CO 3 / perovskite layer (MAPbI3)/ sprio-OMETAD/ Au back electrode. The obtained samples were characterized by X-ray diffraction (XRD), ultraviolet/ visible spectrophotometer (UV-Vis), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and monochromatic incident photon-to-electron conversion. IPCE). In this experiment, six different concentrations of Cs 2 CO 3 were used, 0M (0.90), 0.01M (1.19), 0.02M (1.37), 0.03M (1.55), 0.04M (1.06), 0.05M (0.59). We found 0.03 M cesium is the most suitable concentration for modifying the electron transport layer. Compared to unmodified solar cells, adding a modified layer does not affect the size and thickness of the electron transport layer. The photoelectric conversion efficiency has also increased from 0.90 to 1.55%.