Researchers at the Ecole Polytechnique Federale de Lausanne in Switzerland and a collaborative team from Nanjing University of Aeronautics and Astronautics, National University of Singapore, University of Ioannina, and Politecnico di Milano have made significant advancements in perovskite solar cell technology. By incorporating rubidium (Rb) into the perovskite lattice structure, they were able to enhance stability and efficiency, achieving champion efficiency levels of 25.77% and 20.65% respectively. The introduction of Rb+ cations at grain domain boundaries and the lattice strain approach led to improved carrier diffusion length, lifetime, and suppression of halide phase segregation. These developments mark a promising step forward in the quest for more efficient and stable solar energy solutions.