Power electronics figure-of-merit of ScAlN

A power figure-of-merit (FOM) of ∼62.6–87.3 GW/cm2 is predicted for ScAlN, which represents a value 5–7 times larger than that of GaN. The parameters for the lattice-matched Sc0.18Al0.82N FOM calculation are investigated by first-principles density functional theory (DFT) calculations with the local density approximation. An energy gap of 5.65 eV and an electron effective mass of 0.46m0 are obtained from the DFT band structure calculation of Sc0.1875Al0.8125N. The electron mobility of Sc0.18Al0.82N is simulated based on Boltzmann transport equations, which consider scatterings by ionized impurities, dislocations, alloy scattering, acoustic phonons, and optical phonons. The remarkable power FOM shows that lattice-matched Sc0.18Al0.82N possesses a large breakdown voltage and low specific on-resistance, which suggests the great potential for Sc0.18Al0.82N to be implemented in high-voltage power electronics for improved device performance.