Band structure of wurtzite-like Ga_xAl_(1-x)N solid state alloys

摘要

The band structure of the Ga_xAl_(1-x)-N (GAN) (with x = 0.15, 0.52 and 0.65) solid crystalline alloys was calculated firstly using a new approach of calculations. This approach includes the use of the orthogonalisation procedure for the plane wave basis set with respect to the core-like states and the application of the PA screening procedure. Main one-electron methods of band energy calculations give considerable disagreement with available experimental data. In this paper, it is shown that a better agreement with experiment is achieved when the NCPP wave functions are orthogonalised with respect to the 3d-Ga core-like states. The comparison of the experimental data (ellipsometric, X-ray photoelectron spectroscopy (XPS)) with the calculated ones (FLAPW, LMTO, LCAO, NCPP, etc.) indicates that the orthogonalised NCPP-local-density functional (LDF)-PA method seems to be substantially more appropriate for describing the experimental data in the case of solid alloys.