In this podcast episode, MRS Bulletin’s Laura Leay interviews David Cahen from the Weizmann Institute of Science, Israel, about the impact surface defects have on bulk properties, specifically in the case of lead halide perovskites. In a perspective he co-authored, Cahen connected numerous experimental data from other researchers that exposed this phenomenon. By understanding how surface defects control the material’s electronic behavior, researchers can pursue new materials for the development of long-lasting devices. This work was published in a recent issue of Advanced Materials.