Terahertz radiating device based on semiconductor coupled quantum wells

Abstract

A method is presented for fabricating a semiconductor device operable to generate a THz spectral range radiation in response to an external field. According to this method, a heterostructure is formed from selected layers. The layers include at least first and second semiconductor layers made of materials having a certain initial overlap between the valence band of the second layer material and the conduction band of the first layer material. The heterostructure layers are arranged with a selected layout providing a quantum mechanical coupling between an electron quantum well (EQW) in said first layer and a hole quantum well (HQW) in said second layer. The layout is selected so as to define a predetermined arrangement of a plurality of energy subbands and a predetermined dispersion of these subbands to define a desired effective overlap between the energy subbands of said conduction and valence bands. This enables the device operation for generation of the THz spectral range radiation originating from multiple radiative transitions of non-equilibrium carriers including at least one transition from transitions between the following: energy subbands of the EQW, energy subbands of the HQW, and ground energy electron subband of the EQW and ground energy hole subband of the HQW.