Power beaming for space exploration: electrical and mechanical study of a single junction thin photonic power converter (PPC) in a lunar environment

Laser power transmission (LPT) is an emerging technology that enables distanced wireless power transmission, facilitated by advances in high-efficiency lasers and photonic power converters (PPCs). As lunar exploration gains renewed momentum, ensuring continuous power in permanently shaded regions where solar irradiance is limited is a critical challenge. This study investigates the energy conversion efficiency and thermomechanical stability of single-junction thin InAlGaAs-based PPCs under lunar conditions. The temperature-dependent photo-response of PPCs was measured inside a cryogenic vacuum chamber under 980 and 1064 nm laser illumination at varying power levels. Under 1064 nm laser illumination, the optimal temperature range is from 190 to 250 K with over 40% efficiency. At 77 K, PPC efficiency was higher under 980 nm light than under 1064 nm light due to photovoltaic cell material band gap widening at low temperatures. A COMSOL Multiphysics finite element model was applied to simulate heat transfer and mechanical stress under extreme lunar day-night cycles and to evaluate the risk of material degradation, such as delamination and fatigue, under cyclic thermal loading. The simulations incorporated Gaussian-distributed laser input, solar radiation during lunar daytime, radiative cooling, and ground heat exchange to replicate realistic lunar environments. Results indicate that the indium material stress is between 1.5 and 5 MPa, which is close to its yield stress of 6.1 MPa. By combining experimental and simulated results, the study enhances understanding of PPC behavior in LPT applications in extreme space conditions, supporting material selection and system design for reliable, long-duration lunar and off-Earth power use.