  As 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. Wide band gap (WBG) semiconductors tend to exhibit large
breakdown field, allowing high operating voltages. Currently explored WBG
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 ($\beta$-Ga$_2$O$_3$), or cannot be suitably doped (AlN). We
conduct a computational search for novel semiconductors across 1,340 known
metal-oxides using first-principles calculations and existing transport models.
We calculate the Baliga figure of merit (BFOM) and lattice thermal conductivity
($\kappa_L$) to identify top candidates for n-type power electronics. We find
40 mostly ternary oxides that have higher $\kappa_L$ than $\beta$-Ga$_2$O$_3$
and higher n-type BFOM than SiC and GaN. 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$_2$Ge$_2$O$_7$, Mg$_2$GeO$_4$, and InBO$_3$ 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. These materials could help
advance power electronic devices for the future grid.
