Effect of interface phonons on the functioning of quantum cascade detectors operating in the far infrared range

The spectral characteristics of a cascade of broadband quantum cascade detector, functioning in the far IR range, renormalized by the interaction with all modes of interface phonons are studied using the Green’s function method. Partial contributions into the magnitudes of shifts and decays of electron operating states due to their configurational interactions with all states of the cascade in the processes of emission and absorption of phonons are investigated. It is shown that interaction with interface phonons leads to low-energy shift and decay of operating states of the electron, with their magnitudes increasing at bigger temperature. It is shown that when the width of the potential barrier, which is located in the double-well active region, varies both the shifts and decays of high-energy operating states drastically increase.