Enhanced Efficiency of Highly Transparent, Conductive Ba–Sb Co-Doped SnO ₂ Thin Films for DSSC Applications

A highly conductive, transparent conducting electrode (TCE) based on Ba and Sb codoped tin oxide (BATO) has been successfully spray-deposited for dye-sensitized solar cell (DSSC) applications, offering a promising alternative to conventional fluorine-doped tin oxide/indium tin oxide (FTO/ITO) electrodes. ATO is one of the most extensively studied TCE materials. However, its commercialization remains limited due to suboptimal electrical conductivity and optical transparency. The present research focuses on enhancing these properties by introducing Ba as a codopant in ATO thin films. Barium codopant effectively decreases the grayish color and helps optimize oxygen-vacancy density, which enhances electrical conductivity in ATO thin film. The spray-deposited large-area (10 × 10 cm 2 ) BATO thin film exhibits an enhanced optical transmittance of 86%, a low resistivity of 4.605 × 10 –4 Ω·cm, and a minimum sheet resistance of 13.7 Ω/□ significantly outperforming the corresponding ATO film. Importantly, the suitability of BATO and ATO electrodes was evaluated in DSSC devices, and the obtained results were compared to those of DSSCs employing commercial FTO electrodes. A power conversion efficiency (η) of 3.27% was recorded for the DSSC employing the BATO electrode, outperforming the ATO-based counterpart, which exhibited an efficiency of 2.39%. Interestingly, the alternative BATO electrode significantly reduces the reliance on indium-based TCOs and mitigates the optimization challenges associated with FTO electrodes, thereby contributing to a more cost-effective fabrication of DSSC solar cell devices.