n-Ga₂O₃/p-SnS heterojunction thin-films based transparent photovoltaic device

Due to the urgent requirement of transparent photovoltaics (TPVs) for building integrated applications, solar-blind photodetectors, and high-power devices, the immediate necessity is to develop solar cells with high transparency and good photovoltaic performance. The wide bandgap Ga₂O₃ has attracted significant attention for its excellent optoelectrical properties; however, the role of Ga₂O₃ in inorganic TPV is least explored yet. The wide bandgap Ga₂O₃ may give the device high optical transmittance in the UV to the NIR region by absorbing harmful UV radiations. Herein, we propose and study a novel, eco-friendly sputter-grown p-n heterojunction thin-films device by utilizing n-Ga₂O₃ and p-SnS for TPVs applications. The Ga₂O₃/SnS heterojunction device is tested for the transparent light harvester, and its photovoltaic performance is improved using variation in Ga₂O₃ layer thickness. All fabricated devices demonstrated optical transmittance of ~70 ± 2 % in the near-infrared (NIR) region and ~50 ± 2 % in the visible light region. By optimizing the layer thickness of Ga₂O₃ thin-film, the Ga₂O₃/SnS heterojunction quality was significantly improved and achieved a high photocurrent density of 1.15 mA/cm² and the open-circuit voltage of 527 mV. Our fabricated device showed a power conversion efficiency of 2.9 % under UV light illumination. Furthermore, the proposed transparent photoelectric device exhibited an excellent photovoltaic effect, confirming the potential applications of the Ga₂O₃/SnS heterojunction for advanced optoelectronics.