2025/03/05 by Lee, Cheng-Wei, Egbo, Kingsley, Garrity, Emily +4 · 1 citation
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2503.03619
In this paper we investigate, computationally and experimentally, the phase stability, electronic structure properties, and the propensity for n-type doping of In2X2O7 (X=Si, Ge) ternary oxides. This family of materials contains promising novel wide-gap semiconductors based on their estimated high n-type Baliga figures of merit and acceptable thermal conductivity for power electronics applications. Here, we find that both In2Si2O7 and In2Ge2O7 to be n-type dopable, with Zr providing between 1016 and above 1021 cm-3 net donor concentrations under O-poor conditions, depending on the chemistry, structure (ground-state thorvetite or high-pressure pyrochlore) and synthesis temperature. Initial thin-film growth and annealing leads to polycrystalline In2Ge2O7 thin films in thorvetite structure with band gap over 4 eV, and confirms Zr doping predictions by achieving electron concentrations at 1014-1016 cm-3 under O-rich condition. While future epitaxial growth development is still needed, this study establishes In2X2O7 as promising n-type wide-gap semiconductors for power electronic applications.