Vibration Spectra of Quasi-confined Optical Phonon Modes in an Asymmetric Wurtzite Al_xGa_(1-x)N/GaN

• 出 处: Communications in Theoretical Physics
• 发表日期: 2007年02期
• 关键词: confined phonon symmetric expanding x)N/GaN/Al_yGa dielectric asymmetric electro

Based on the dielectric continuum model and Loudon’s uniaxial crystal model,the properties of the quasi-confined (QC) optical phonon dispersions and the electron-QC phonons coupling functions in an asymmetric wurtzitequantum well (QW) are deduced via the method of electrostatic potential expanding.The present theoretical schemecan naturally reduce to the results in symmetric wurtzite QW once a set of symmetric structural parameters are chosen.Numerical calculations on an asymmetric AIN/CaN//Al_(0.15) Ca_(0.5)N wurtzite QW are performed.A detailed comparisonwith the symmetric wurtzite QW was also performed.The results show that the structural asymmetry of wurtzite QWchanges greatly the dispersion frequencies and the electrostatic poteutial distributions of the QC optical phonon modes.

Based on the dielectric continuum model and Loudon’s uniaxial crystal model, the properties of the quasi-confined (QC) optical phonon dispersions and the electron-QC phonons coupling functions in an asymmetric wurtzite quantum well (QW) are deduced via the method of electrostatic potential expanding The present theoretical scheme is naturally reduced to the results in a symmetric wurtzite QW once a set of symmetric structural parameters are chosen. Numerical calculations on an asymmetric AIN / CaN // Al_ (0.15) Ca_ (0.5) N wurtzite QW are performed .A detailed comparisonwith the symmetric wurtzite QW was also performed. the results show that the structural asymmetry of wurtzite QWchanges greatly the dispersion frequencies and the electrostatic poteutial distributions of the QC optical phonon modes.