Electron effective masses of Scx Al1- x N and Alx Ga1- x N from first-principles calculations of unfolded band structure

The electron effective masses of Sc x Al 1 - xN and Al x Ga 1 - xN, two of the most promising wide bandgap materials for power and RF electronic applications, have been calculated using the predictions of the density functional theory (DFT). More specifically, the unfolding technique has been adopted to extract the effective band structure of the two alloys under investigation. It has been found that the AlGaN effective masses m - approximately follow the Vegard law. On the contrary, due to the larger amount of disorder inside the crystal, the ScAlN shows a non-monotonic change of m - as a function of the Sc concentration, which requires the DFT calculations to be consistently performed for an accurate prediction. The ScAlN effective masses as a function of Sc content have been reported in the range 0 ≤ x ≤ 0.25 for the first time.