Elastic constants and Debye temperature of wz-AlN and wz-GaN semiconductors under high pressure from first-principles

摘要

First-principles calculations were performed to study the elastic stiffness constants ($C_{ij}$) and Debye temperature ($e???_D$) of wurzite (wz) AlN and GaN binary semiconductors at high pressure. The lattice constants were calculated from the optimized structure of these materials. The band gaps were calculated at e??¤ point using local density approximation (LDA) approach. The unit cell volume, lattice parameters, e?‘?/e?‘?, internal parameter (e?‘￠), elastic constant ($C_{ij}$), Debye temperature ($e???_D$), Hubbard parameter (e?‘?) and band gap ($E_g$) were studied under different pressures. The bulk modulus ($B_0$), reduced bulk modulus ($B'_0$) and Poisson ratio ($vee$) were also calculated. The calculated values of these parameters are in fair agreement with the available experimental and reported values.