Embedding TiO2 Nanodiscs in the MoSe2 Electron Transport Layer Boosts the Efficiency of Perovskite Solar Cells

To improve the performance of inverted perovskite solar cells, we introduce a novel approach to enhance the devices’ efficiency notably. Our novel strategy incorporates a cutting-edge metasurface-based reflector featuring TiO 2 nanodiscs within a MoSe 2 layer, employed as an electron transport layer (ETL). Demonstrating a substantial improvement in light reflection from the lower part of the structure, the TiO 2 nanodiscs as a metasurface-based reflector enhance electron transfer. Notably, the metasurface-based perfect reflector, incorporating TiO 2 nanodiscs, outperforms other TiO 2 nanocube variations with an impressive light reflectance of 97.95%. Exploring different materials for electron transport layers (ETLs) and hole transfer layers (HTLs), we identify MoSe 2 as a potent secondary absorbent material, featuring a smaller bandgap than the primary absorbent MAPbI 3 , thereby intensifying the electric field within the active layer and improving Power Conversion Efficiency (PCE). In the final evaluation, our inverted metasurface-based device structure (ITO/Cu 2 O (HTL)/MAPbI 3 /TiO 2 nanodiscs and MoSe 2 (ETL)/aluminum/SiO 2 ) significantly enhances the solar cell’s electrical characteristics compared to the planar reference structure (ITO/CuSCN/MAPbI 3 /TiO 2 /aluminum), with noteworthy increases in J sc , V oc , and PCE values from 17.98 mA/cm 2 to 21.91 mA/cm 2 , 1.03 V to 1.07 V, and 15.33% to 19.17%, respectively. Our proposed inverted metasurface-based device structure represents a promising potential in the construction of high-performance perovskite solar cells.