Interface phonon spectrum and electron-phonon interaction in AlGaN/GaN/AlGaN nanostructures

The paper investigates the properties of electron and interface phonon states, and the influence of electron-interface-phonon interaction on the electron spectral characteristics in AlGaN/GaN/AlGaN nanostructures, as a key element of nanodevices. Using the Green’s function method at cryogenic temperatures, the mass operator was calculated. This made it possible to investigate the renormalized spectral characteristics of electron states due to interaction with all branches of interface phonons. We studied the partial contributions of individual phonon branches and configurational interactions to the shifts of the two lowest electron states. It has been established that the interaction with interface phonons at cryogenic temperatures leads to low-energy shifts of all electron states and to damping of only the excited states. The influence of the quantum well’s geometric parameters on the renormalization of the electron spectrum was also analyzed.