FAR-INFRARED EMISSION BY HEATED ELECTRONS IN A TWO-DIMENSIONAL SEMICONDUCTOR SYSTEM

Abstract

In this letter, we present a detailed theoretical study that explores the possibility to use AlGaAs/GaAs-based two-dimensional semiconductor systems (2DSSs) as the far-infrared (FIR) generators at zero-magnetic field and by electrically heated electrons. A simple model from which the intensity of FIR radiation can be calculated as a function of photon frequency is developed by calculating the electron-energy-loss induced by hot-electron interaction with electromagnetic field, mediated by electron-phonon scattering. The main results obtained from the present study are: (1) in a 2DSS, FIR radiation is mainly generated among the different electronic subbands; (2) the polarization of FIR generated from a 2DSS is along the growth direction; (3) the intensity of FIR radiation increases rapidly with increasing energy excitation, i.e., with electron temperature; (4) the frequency of electromagnetic wave generated is around ω~|εm– εn|/ħ with εn the electronic subband energy; and (5) for an AlGaAs-GaAs-AlGaAs single quantum well structure, the frequency of the FIR emission can be tuned by varying the width of the well layer. We have also studied the influence of electron density, lattice temperature, etc. on the FIR emission by heated electrons in 2DSSs.