Optimizing Electron Transport in Crystalline Silicon Solar Cells with Oxygen-Doped Titanium Carbide Layer

Carrier-selective contacts have proven effective in enhancing the efficiency of crystalline silicon (c-Si) solar cells by reducing interface recombination losses and improving conversion efficiency. This study introduces a novel oxygen-doped titanium carbide (TiC_xO_y) electron transport layer (ETL), fabricated via electron beam evaporation. The TiC_xO_y film demonstrated a low contact resistivity (17.74 mΩ·cm²) and work function (4.12 eV), enabling efficient ohmic contact with lightly doped n-type c-Si. When applied as an ETL in c-Si solar cells, TiC_xO_y significantly increased the open-circuit voltage (V_oc) and fill factor (FF), boosting the cell efficiency from 13.14–16.87%. Furthermore, the TiC_xO_y layer enhanced quantum efficiency in the near-infrared spectral range. These findings indicate that TiC_xO_y is a promising ETL material, with potential to advance high-efficiency silicon heterojunction solar cells.