Application of ZnGa2O4:Mn Down-Conversion Layer to Increase the Energy-Conversion Efficiency of Perovskite Solar Cells

The perovskite solar cell is capable of energy conversion in a wide range of wavelengths, from 300 nm to 800 nm, which includes the entire visible region and portions of the ultraviolet and infrared regions. To increase light transmittance of perovskite solar cells and reduce manufacturing cost of perovskite solar cells, soda-lime glass and transparent conducting oxides, such as indium tin oxide and fluorine-doped tin oxide are mainly used as substrates and light-transmitting electrodes, respectively. However, it is evident from the transmittance of soda-lime glass and transparent conductive oxides measured via UV-Vis spectrometry that they absorb all light near and below 310 nm. In this study, a transparent Mn-doped ZnGa₂O₄ film was fabricated on the incident surface of perovskite solar cells to obtain additional light energy by down-converting 300 nm UV light to 510 nm visible light. We confirmed the improvement of power efficiency by applying a ZnGa₂O₄:Mn down-conversion layer to perovskite solar cells.