Researchers at the Korea Institute of Energy Research have set a new world-record power conversion efficiency of 26.7% for a perovskite-CIGS tandem solar cell, surpassing the previous record of 26.3%. This achievement combines high efficiency with a lightweight, flexible form factor by minimizing damage to the perovskite layer and optimizing the structure of the top transparent electrode and charge transport layer to reduce losses. By mitigating interfacial and optical losses, the researchers have improved efficiency and stability in the tandem device, showcasing promising advancements in solar technology for climate solutions.