Characterization and Computational Modeling of Flexible Freestanding GaAs-Based Solar Cells

The development of flexible freestanding single-junction GaAs photovoltaic (PV) cells demonstrates a major innovation in solar technology, providing a lightweight, high-efficiency substitute to traditional silicon-based PV cells. Chemical vapor deposition (CVD) approach is frequently used to deposit graphene “Gr” on a single crystalline substrate. As an innovative point, this study demonstrates that graphene can be deposited by metal–organic chemical vapor deposition (MOCVD) before developing the epilayers on the substrate, which creates highly uniform and smooth interfaces. This research aims to develop flexible freestanding single-junction solar cells based on gallium arsenide (GaAs) and evaluate their photoelectric properties using both experimental and numerical methods. Flexible, freestanding GaAs-based membranes were fabricated using a novel combination of remote epitaxy and MOCVD. Initial experimental characterization under air mass global condition (AM1.5G) (1000 W/m² insolation, 25°C ambient temperature) yielded a power conversion efficiency (PCE) of approximately 9.45%. Through optimization of layer thickness and doping concentrations, this efficiency increased significantly to 19.62%. Numerical simulations conducted in MATLAB and COMSOL Multiphysics validated experimental findings, shedding light on critical mechanisms such as I–V characteristics, carrier generation, and recombination. Performance analysis under terrestrial and extraterrestrial (AM₀) conditions revealed a maximum power output of 27.40 mW with a photocurrent of 28.86 mA under AM₀ spectra. These findings highlight the potential of flexible, high-efficiency GaAs solar cells for diverse energy solutions, including space applications, advancing their utility in terrestrial and extraterrestrial environments.