Efficiency Boost in Perovskite Solar Cells via TiO2 Nanodiscs Embedded in the MoSe2 Electron Transport Layer Revealed by Optoelectronic Simulations

Abstract

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 TiO2 nanodiscs within a MoSe2 layer, employed as an electron transport layer (ETL). Demonstrating a substantial improvement in light reflection from the lower part of the structure, the TiO2 nanodiscs as a metasurface-based reflector enhance electron transfer. Notably, the metasurface-based perfect reflector, incorporating TiO2 nanodiscs, outperforms other TiO2 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 MoSe2 as a potent secondary absorbent material, featuring a smaller bandgap than the primary absorbent MAPbI3, 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/Cu2O (HTL)/MAPbI3/TiO2 nanodiscs and MoSe2 (ETL)/aluminum/SiO2) significantly enhances the solar cell's electrical characteristics compared to the planar reference structure (ITO/CuSCN/MAPbI3/TiO2/aluminum), with noteworthy increases in Jsc, Voc, and PCE values from 17.98 mA/cm2 to 21.91 mA/cm2, 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.