A Computational Search for Ultra-Wide Band Gap Semiconductors for High-power and High-temperature Electronics

As we move toward a more renewable electricity grid, we need to find power electronics that can withstand high power and high voltage. Ultra-wide band gap (UWBG) materials are promising candidates. However, many UWBG materials either lack the thermal properties to dissipate heat (Ga₂O₃), are difficult to synthesize at scale (diamond, c-BN), or are difficult to dope (AlGaN). Using density function theory (DFT), we conduct a high-throughput computational search of >1,500 oxides, nitrides, sulfides, carbides, silicides, and borides. Generalized gradient approximation (GGA) calculations and semi-empirical models are used to evaluate high power electronic performance through the Baliga figure of merit (BFOM) and lattice thermal conductivity (κ_L). The top candidates are further assessed using low-throughput, higher-accuracy hybrid calculations. Our results find more than 28 promising candidates (65% oxides and 35% nitrides) that surpass current WBG materials (Ga₂O_3, SiC-4H, GaN). We also conduct a qualitative assessment of n-type dopability by evaluating the governing material properties for acceptor defects. This work allows confident selection of materials for experimental investigation. Ref: Energy Environ. Sci., 2019, 12, 3338.