Our research focuses on Optoionics, an emerging field that is conceptually analogous to optoelectronics, where light–matter interaction is coupled to ionic motion instead of purely electronic effects. Optoionic principles enable a wide range of applications, including solar batteries, photocatalysts, memristors, and radiation detectors. A central goal of our group is the development of all-solid-state solar batteries, exploring different design concepts such as self-charging and externally assisted charging architectures. We combine fundamental understanding of optoionic mechanisms with the development of dedicated, cell-level testing methods. Our work is embedded in the SolBat Center, in close cooperation with the Max Planck Institute.