Structural design of laser-photovoltaic power converter

As part of research and development into the Laser Based Space Solar Power System (L-SSPS), a laser-photovoltaic power converter for 1.07 μm laser light has been researched at the Japan Aerospace Exploration Agency (JAXA). To improve conversion efficiency of the InGaAs laser-photovoltaic power converter, photovoltaic properties under 1.07 μm laser illumination were calculated in this study with varying the structural parameters such as In/Ga ratio, layer thickness, p/n-junction depth and carrier concentration of the InGaAs cell. The conversion efficiency of 42.6 % at 0.3 W/cm² laser irradiance and 300 K cell temperature was obtained by optimizing all the structural parameters, indication that the thickness and carrier concentration optimization leads remarkable improvements in conversion efficiency.