InGaN photovoltaic cells for applications in laser power beaming

We tested the optical wireless power transmission (OWPT) using InGaN photovoltaic cells and lasers below 400 nm. As a result, 24.5% and 20.8% photoelectric conversion efficiencies were obtained at laser power densities of 16.5 mW/cm² and 398 mW/cm², respectively. The conversion efficiency decreased as incident laser power increased. On the other hand, the conversion efficiencies increased with increasing the temperature of the InGaN photovoltaic cells. We investigated the causes of these phenomena and found that lower resistance and improved crystal quality of InGaN cells significantly improve conversion efficiency further.