Earth-abundant thin films
Solar cells with thin-film absorbers require 100x less active-layer material than crystalline silicon, enabling low costs and potential for roll-to-roll fabrication. While traditional thin-film materials (cadmium telluride and copper indium gallium diselenide) rely on scarce or toxic species, “Earth-abundant” alternative materials have rarely demonstrated efficiencies far above 10%. Demonstrating a stable, readily manufacturable, Earth-abundant thin-film material with efficiency potential approaching 20% could be a game-changing development.
Innovations: To accelerate the efficiency enhancement of Earth-abundant thin films, including tin sulfide (SnS) and cuprous oxide (Cu2O), we are applying a structured defect-mitigation framework inspired by our experience with crystalline silicon technology. Taking a rational approach to improving the bulk and interface quality, we have demonstrated meaningful efficiency enhancements in both material classes. This work suggests that many alternative PV materials are not fundamentally limited by a law of physics, but rather, by limited engineering investments.