High-Throughput Screening of High-Entropy Fluorite-Type Oxides as Potential Candidates for Photovoltaic Applications

摘要

High-throughput (HT) synthesis and HT characterization techniques arebecoming increasingly important due to the ever-increasing complexity ofmaterials and applications of advanced functional compounds. This workreports on the high-throughput compilation of material libraries ofhigh-entropy oxides with fluorite crystal structure and tunable band gaps to beused as, e.g., semiconductors for photovoltaic applications. The materiallibraries cover the high-entropy range of rare-earth oxides with 5, 6, and 7different cations (Ce, La, Sm, Pr, Tb, Y, and Zr) in near equimolarconcentrations, but also the medium entropy range with 4 cations. Theatmosphere used during or after synthesis is found to have a large effect onthe band gap of these materials. Multivalent rare-earth cations such asCe/Pr/Tb enable reversible tuning of the band gap between 2.0 and 3.5 eVupon calcination under various oxidizing and reducing atmospheres. Thehigh-entropy fluorite oxides with smaller band gaps exhibit high electronmobility and transport energy levels compatible with common solar cellarchitectures.