Influence of Pressure on Polaron Energy in a Wurtzite GaN/Al_xGa_(1-x)N Quantum Well

摘要

The influence of hydrostatic pressure on the polaron energy level in wurtzite GaN/Al_xGa_(1-x)N quantum well is studied by a Lee-Low-Pines variational method, and the numerical results of the ground state energy, transition energy and contributions of different phonons to polaron energy (polaron effects) are given as functions of pressure p and composition x. The results show that the ground state energy and transition energy in the wurtzite GaN/Al_xGa_(1-x)N quantum well decrease with the increase of the hydrostatic pressure p, and increase with the increase of the composition x. The contributions of different phonons to polaron energy with pressure p and composition x are obviously different. With the increase of hydrostatic pressure, the contribution of half-space phonon, confined phonon and the total contribution of phonons of all branches increases obviously, while the contribution of interface phonon slowly increases. With the increase in composition, the contribution of interface phonon decreases and the contribution of half-space phonon increases slowly, while the contribution of confined phonon and the total contribution of phonons increases significantly. In general, the electron-optical phonon interaction play an important role in electronic states of GaN/Al_xGa_(1-x)N quantum wells and can not be neglected.