Affiliation:
1. Rzhanov Institute of Semiconductor Physics Siberian Branch of Russian Academy of Sciences 13 Lavrentyev Novosibirsk 630090 Russia
2. Photovoltaics Laboratory Ioffe Institute 26 Polytechnicheskaya Street St.‐Petersburg 194021 Russia
Abstract
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.