Hydrophobic SiOxCy :H Thin Films Deposited by PECVD for Photovoltaic Module Protection

This study explores the optimization of SiO _x C _y :H thin films fabricated under varying radio frequency power conditions to achieve enhanced water repeal while preserving photovoltaic (PV) performance. Thin films derived from hexamethyldisiloxane were deposited on glass substrates via plasma-enhanced chemical vapor deposition (PECVD). The sessile drop technique was used to assess the water contact angle. Our findings indicate that SiO _x C _y :H films deposited at 200 W and 300 W exhibit hydrophilic behavior (θ < 90°), whereas the film produced at 100 W achieves hydrophobicity (θ > 90°), optimizing surface wettability for water-repellent applications. Notably, applying the 100 W film to a solar cell resulted in minimal efficiency loss (0.47%) and only a 1% decrease in fill factor, confirming that PV performance remained practically unaltered. These findings highlight the potential of SiO _x C _y :H thin films fabricated at optimized conditions to provide effective protection against moisture without compromising solar cell functionality.