Material‐Driven Design of OMO‐Perovskite‐OMO Solar Cells for Bifacial and Semi‐Transparent Photovoltaic Applications

The growing demand for efficient semi‐transparent and bifacial perovskite solar cells (PSCs) calls for device architectures that balance optical transparency with high photovoltaic performance. This work presents the design and optimization of a [oxide–metal–oxide (OMO)–perovskite–OMO] device stack configured as Oxide 1/Ag/SnO 2 /Perovskite/NiO/Ag/Oxide 2. A key advantage of this architecture is that the overcoat oxide of the bottom transparent electrode (TE) and the undercoat oxide of the top TE function as electron and hole transport layers, eliminating the need for separate charge transport layers. Variable‐angle spectroscopic ellipsometry is employed to get refractive index data for each layer used for the optimization via optical modeling. A comprehensive evaluation of 100 material combinations revealed that the transparent electrode (TE) with the highest average visible transmittance (AVT) does not necessarily yield the best device performance. This dataset offers a practical framework for selecting TE materials best suited for specific device designs. The optimized device achieved a J SC of 19.85 mA/cm 2 for bifacial operation and an AVT of 12.40% for semi‐transparent device application. Adding an optical spacer further boosted the J SC to 20.80 mA/cm 2 . This approach provides a design strategy to advance PSCs toward building integrated photovoltaic, solar windows, and automotive applications.