Bandgap Change in Short-Period InN/AlN Superlattices Induced by Lattice Strain

III–V GaN-based nitride semiconductors have attracted interest because their bandgaps can be tuned by constructing alloys and superlattices, and by applying lattice strain. Herein, the influence of uniaxial and equibiaxial strains on the bandgaps of short-period InN/AlN superlattices is examined using first-principles calculations. For the uniaxial strain, the bandgaps change in the same manner when the superlattices are strained in the a- and m-axis directions; however, the bandgaps change in a different manner when the superlattices are strained in the c-axis direction. Even when equibiaxial strain is applied, the change in bandgap depends on the direction in which the strain is applied.