Aqua-powered hybrid solar cell using amorphous conformal Ga2O3 thin-film

Abstract

Clean energy generation is a primary demand to neutralise carbon emissions. Photovoltaics are the best candidates for clean energy. Water is a reliable and sufficient resource for future clean energy generation, as it can be used to enhance photovoltaic performance in a hybrid system. This study designs and investigates a novel aqua-voltaic hybrid solar cell by integrating an ultra-thin gallium oxide layer (2.3 nm) with a polycrystalline silicon solar cell under water-based conditions. The amorphous Ga₂O₃ layer grown by sputtering enhances optical absorption, reduces surface reflectance in the ultraviolet (UV) region, and serves as a protective barrier against environmental degradation. Photovoltaic characterisations reveal an efficiency enhancement from 19.04 % to 21.56 % in Si solar cell when Ga₂O₃ and water are introduced. Under illumination, electrochemical impedance spectroscopy (EIS) exhibits capacitance and resistance, indicating strong interfacial charge dynamics. These phenomena are attributed to electronic double-layer capacitance, quantum capacitance modulation, and charge redistribution at the Ga₂O₃-water interface. The results illustrate the dual role of water in enhancing charge transport while influencing surface-state interactions, leading to improved solar cell performance. This work provides insights into the interaction of semiconductor-liquid interfaces and offers an efficient hybrid energy harvesting technologies.