Strain and crystal field splitting inversion in III-Nitrides

Abstract

The wurtzite phase group III-Nitrides (AlN, GaN, InN) have attracted great interest due to their successful applications in the optoelectronics since the 90's. In this paper we perform a comprehensive study of AlN, GaN and InN structural elastic and electronic properties using hybrid and conventional Density Functional Theory, presenting a comparison of the features of the three compounds. We perform a direct comparison of the features of their electronic structures, including the inversion of the top valence band associated with a negative crystal field splitting and its relation to the challenges of acceptor-doping on AlN systems. With the determination of elastic constants and the Young modulus we provide a simple model to connect a deformation energy associated with the parameter u and the effective crystal-field splitting, showing a direct relation among internal strain and the crystal-field splitting.

DFT2kp: Effective kp models from ab-initio data

“…Using the basis functions from wurtzite materials. For the valence bands, one always gets Γ7 ⊕ 2 Γ9 , however, the internal ordering of these valence bands may change between materials and it can be highly sensible to the choice of density functional [28,60,112,113]. The numerical coefficients c j found for GaN, GaP, InP are shown in Appendix C, and the resulting band structures are shown in Figs.…”