Expansion ratio dependence of lattice vibration of GaN using ab initio molecular dynamics calculations

Temperature dependence of Raman shift wavenumbers are important for the measurements of heat distribution of high-power GaN devices. In this study, calculated results of vibrational modes of ground state structure and some expanded structures of wurtzite type gallium nitride were presented using ab initio molecular dynamic (AIMD) simulations. Frequency analyses have been done for these calculated results and compared with the experimental results of temperature dependence of Raman spectra. Good agreement was achieved between the calculated and the experimental results quantitatively. AIMD would be a useful tool for the prediction of vibrating analysis for III-N systems.