Computational Identification of Ternary Wide-Band-Gap Oxides for High-Power Electronics
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-12-20 |
| Journal | PRX Energy |
| Authors | Emily M. Garrity, ChengâWei Lee, Prashun Gorai, M. Brooks Tellekamp, Andriy Zakutayev |
| Institutions | National Renewable Energy Laboratory, Colorado School of Mines |
| Citations | 12 |
Abstract
Section titled âAbstractâAs electricity grids become more renewable energy compliant, there will be a need for novel semiconductors that can withstand high power, high voltage, and high temperatures. Currently used or explored wide-band-gap materials for power electronics are costly (GaN), difficult to synthesize as high-quality single crystals (SiC) and at scale (diamond, BN), have low thermal conductivity (ÎČ-Ga<sub>2</sub>O<sub>3</sub>), or cannot be suitably doped (AlN). We conduct a computational search for novel semiconductors across 1340 known metal oxides using first-principles calculations and existing and improved transport models. We calculate the Baliga figure of merit (BFOM) and lattice thermal conductivity ($Îș_L$) to identify top candidates for n-type power electronics. We find 47 mostly ternary oxides that have higher $Îș_L$ than ÎČ-Ga<sub>2</sub>O<sub>3</sub> and higher n-type BFOM than SiC and GaN. We use the branch point energy to rank the likelihood of n-type extrinsic doping, further reducing our top candidates to 14 previously unexplored compounds. Among these, several material classes emerge, including 2-2-7 stoichiometry thortveitites and pyrochlores, II-IV spinels, and calcite-type borates. Within these classes, we propose In<sub>2</sub>Ge<sub>2</sub>O<sub>7</sub>, Mg<sub>2</sub>GeO<sub>4</sub>, and InBO<sub>3</sub> for power electronics as they are the most favorable for n-type doping based on our preliminary evaluation and could be grown as single crystals or thin-film heterostructures.