Polaron Self Energy And Relative Parameters In Wurtzite Ternary Mixed Crystals A_xB_1-xC

The polaron self energy and parameters related to the electron-phonon interaction ?such as:optical phonon frequeny, static dielectric constants, high frequency dielectric constants and electron-phonon coupling constants? in wurtzite ternary mixed crystal A_xB_1-xC materials are investigated in the thesis. The numerical results of the parameters as functions of the composition x are calculated in wurtzite ternary mixed crystals Al_xGa_1-xN, In_xGa_1-xN and Mg_xZn_1-xO, and the results are compared with the results of using linear interpolation method.The results show that the correlation parameters and polaron self energy in wurtzite ternary mixed crystal A_xB_1-xC increase obviously with increasing composition x.The high frequency dielectric constants in In_xGa_1-xN increases with increasing the composition x, but the high frequency dielectric constants in Al_xGa_1-xN and Mg_xZn_1-xO decrease with increaseing the composition x. The static dielectric constant of In_xGa_1-xN material varies linearly with the increase of composition, while that of Al_xGa_1-xN and Mg_xZn_1-xO are nonlinear variation. With increasing composition x. the optical phonon frequeny, electron-phonon coupling constants and polaron self energy in In_xGa_1-xN decrease, but the optical phonon frequeny, electron-phonon coupling constants and polaron self energy in Al_xGa_1-xN and Mg_xZn_1-xO increase. The results show that the numerical results of the optical phonon frequency and high frequency dielectric constant, electron-phonon interaction coupling constants and polaron self energy obtained by relevant formulas are similar to the results based on the method of linear interpolation, but the static dielectric constant exists some deviation.Therefore, in all above the three kinds of materials, optical phonon frequency, high frequency dielectric constants, electronic-phonon interaction coupling constants can be directly obtained by using the method of linear interpolation, but the static dielectric constant has certain error by using a linear interpolation method.