Raman spectra of undoped GaN and Mg-doped GaN films grown by metal-organic chemical-vapor deposition on sapphire are investigated between 78 and 573K.A peak at 247cm -1 is observed in both Raman spectra of GaN and Mg-...Raman spectra of undoped GaN and Mg-doped GaN films grown by metal-organic chemical-vapor deposition on sapphire are investigated between 78 and 573K.A peak at 247cm -1 is observed in both Raman spectra of GaN and Mg-doped GaN.It is suggested that the defect-induced scattering is origin of the mode.The electronic Raman scattering mechanism and Mg-related local vibrational mode are excluded.Furthermore,the differences of E_2 and A_1(LO) modes in two samples are also discussed.The stress relaxation is observed in Mg-doped GaN.展开更多
文摘Raman spectra of undoped GaN and Mg-doped GaN films grown by metal-organic chemical-vapor deposition on sapphire are investigated between 78 and 573K.A peak at 247cm -1 is observed in both Raman spectra of GaN and Mg-doped GaN.It is suggested that the defect-induced scattering is origin of the mode.The electronic Raman scattering mechanism and Mg-related local vibrational mode are excluded.Furthermore,the differences of E_2 and A_1(LO) modes in two samples are also discussed.The stress relaxation is observed in Mg-doped GaN.
