(138c) From Self-Assembled Mesoporous Thin Films to Kesterite Solar Cells

Given the terawatt-scale of future energy needs, the most promising future photovoltaic materials should be Earth abundant with their primary mineral resources distributed across several geographic regions and their supply chains robust to reduce concerns of price volatility. In addition, the process of forming the solar cell should be scalable, low-cost, and not utilize dangerous or toxic materials. One of the strongest candidates appears to solution processed kesterite structures of Cu₂ZnSn(S,Se)₄ or similar alloys. Our most recent result is the development of benign-solvent molecular-inks that yield ~11% efficient solar cells from these kesterites. This presentation will focus on the materials science and physics that led from a starting point focused on the development of nanostructured thin film photovoltaics based on self-assembled mesoporous ceramic films to the current state-of-the-art. We will show the results of composition spread experiments coupled with spatially resolved photoluminescence and a new theoretical framework to analyze photoluminescence that reveal the effects of native point defects and doping on material quality and device performance.