Designing of Lightweight and Ultrathin III‐V/Ge Solar Cells for Flexible Space and Terrestrial Photovoltaic Blankets

The method described in this article offers a simple and convenient way to obtain highly efficient, ultrathin, and flexible solar cells (SCs) based on III‐V/Ge heterostructures. This is achieved by thinning Ge to several tens, or even a few units of microns, which accounts for up to 95% of the total thickness and weight of a SC. The only low‐temperature thermal peelable tape REVALPHA as a temporary carrier supports and saves the heterostructure along the process route. The carrier is then easily and cleanly removed by heating without damaging the thinned SC. The temporary carrier provides a reliable transfer of the thinned SC with a developed low‐temperature (i.e., without annealing) indium back contact to an arbitrary light and flexible substrate (Kapton or carbon sheet). The possibility of creating highly efficient, ultrathin, and ultralight SCs on a flexible carrier is demonstrated using mass‐produced GaInP/Ga(In)As/Ge heterostructures. Based on the results obtained, a possible architecture and technology for assembling coupons from ultrathin solar cells based on any III‐V/Ge heterostructures on a Kapton or carbon carrier for space and terrestrial applications are proposed.