Zeno Karl Schindler Award - 2025 - Christian Wolff

For his multiple contributions to the field of perovskite and perovskite-silicon solar cells, allowing among others the first worldwide demonstration of tandem perovskite-silicon solar cells with over 30% efficiency, world record triple junction solar cells, as well as perovskite solar cells with remarkable stability. His achievements open key pathways for providing low-cost clean electricity beyond standard silicon solar cells.

Solar energy conversion in the form of solar cell modules is a cornerstone of the transition towards a net-zero society. With increasing deployment new problems concerning competing space usage and material criticality (e.g., silver or indium) arise. A promising way out of these dilemmas is to make better, low-cost, more material-efficient solar cells. Among different approaches so-called multi-junction solar cells based on halide perovskites are particularly interesting. They are made from earth-abundant materials in a low-cost fashion and can be readily combined with the dominating solar cell technology – crystalline silicon. Halide perovskites -as a class of materials- offer wide tunability, which in turn means that a wide range of materials need to be tested – requiring test methods that provide rapid feedback. By developing and applying luminescence-based characterization techniques, my team and I could rapidly identify material combinations that allow to make more efficient multijunction solar cells combining perovskites with silicon, well beyond the limits of silicon. This led to several world records over the past years and also sparked industry to invest in the technology having a lasting impact.