InGaN photovoltaic laser power converters for atmospheric and submarine optical wireless power transfers

Optical Wireless Power Transfer (OWPT) has surfaced as a transformative technology among long-range wireless power transmission options, capable of delivering kilowatts of power across kilometric distances. By eliminating physical connections, OWPT enables energy supply in harsh environments such as the deep ocean, outer space, or remote terrestrial locations with complicated access. However, the main challenge hindering its widespread adoption is the reduced system efficiency, particularly at high-power densities (≥ 100Wcm^-2 ), where the efficiency of Photovoltaic Laser Power Converters (PVLPC) experiences significant degradation. To address this limitation, there is an urgent need for PVLPCs that can efficiently withstand intense monochromatic irradiances. Previous theoretical studies have identified InGaN as a promising material for improving state-of-the-art performance due to its tunable wide bandgap, which can be optimized for the specific transmission medium, and reduce series resistance losses. This work investigates the impact of the energy gap on efficiency across varying light intensities and its effect on overall system performance in both air and underwater environments. The results indicate that efficiencies as high as 76.5% can be achieved at 95Wcm^-2 , and over 71% at 1000 Wcm^-2 , for the highest energy gap alloy, In0.1Ga0.9N. Furthermore, system efficiencies of 69.7% are estimated for 10 km atmospheric transfers, and 52.6 and 36.9% for 20 and 40 m underwater transmissions, respectively. This work highlights the potential of InGaN-based PVLPCs to advance OWPT to new performance thresholds.