Intraband transitions at a CsPbBr/GaAs heterointerface in a two-step photon upconversion solar cell.

Two-step photon upconversion solar cells (TPU-SCs) based on III-V semiconductors can achieve enhanced sub-bandgap photon absorption because of intraband transitions at the heterointerface. From a technological aspect, the question arose whether similar intraband transitions can be realized by using perovskite/III-V semiconductor heterointerfaces. In this article, we demonstrate a TPU-SC based on a CsPbBr/GaAs heterointerface.