Ternary Mixed Crystal Effects on the Interface Optical Phonon Spectrum in Wurtzite GaN/AlxGa1-xN Quantum Wells

Based on the dielectric continuum model and modified random-element isodisplacement model, the ternary mixed crystal effects on interface optical phonon and electron-interface optical coupling in GaN/AlxGa1-xN quantum wells are studied in a fully numerical manner. When the aluminium concentration in the range (0.03, 0.13), there exist two branches of interface optical phonons in high frequency range. When the aluminium concentration in the range (0.13, 1.00), there are four branches of interface optical phonons in high and low frequency range. With the increase of aluminium concentration, the frequencies of interface optical phonon almost change linearly. The electron-phonon couplings also almost linearly vary with aluminium concentration in high frequency range. But in low frequency range, the electron-phonon coupling indicate nonlinear changes with increasing aluminium concentration.