POSS Polyimide Sealed Flexible Triple‐Junction GaAs Thin‐Film Solar Cells for Space Applications

Abstract Flexibility and light weight are beneficial to reduce load, reduce volume, integrate device, and is the development trend of space science and technology. However, current solar cells on spacecrafts are still based on rigid triple‐junction GaAs solar cells covered by anti‐radiation glasses, which are heavy, non‐flexible, takes large separate space, and cannot be integrated with a spacecraft. To solve these problems, in this work, a transparent polyhedral oligomeric silsesquioxanes (POSS) polyimide film sealed flexible triple‐junction GaAs thin‐film solar cell has been developed by thermal lamination, with a high photoelectric conversion efficiency of 28.44% (AM0, 25 °C) and stable performance upon a 4.1 × 10²¹ atoms cm⁻² atomic oxygen exposure and an 89.5 ESH ultra‐violet exposure. Systematical space irradiations have been conducted to the transparent POSS polyimide sealing films by ground facilities in terms of atomic oxygen, ultra‐violet, electron, electron and proton, gamma ray, and thermal cycling. Fourier transform infrared spectroscopy, transmittance, mechanical tensile strength has been tested for exploring the mechanism of space environmental effects on transparent POSS polyimide film. This study suggests a transparent POSS polyimide sealed triple‐junction GaAs thin‐film solar cell with promising potentials in flexible, lightweight, integration for durable high‐efficiency power supplies in low and high Earth orbits.