Patent ID: 7176498

Claim:
A semiconductor device operable in a THz spectral range, the device comprising a heterostructure configured to generate THz spectral range radiation in response to an external field applied across it, the heterostructure comprising at least first and second semiconductor layers made of materials providing a certain initial overlap between the valence band of the second layer material and the conduction band of the first layer material, and having a selected layout of the heterostructure layers 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, said selected layout of the layers of the heterostructure defining a predetermined arrangement of a plurality of energy subbands and a predetermined dispersion of these subbands including the substantially equidistant neighboring subbands to define a desired effective overlap between the energy subbands of said conduction and valence bands, thereby creating a condition of the multiple resonant radiative transitions substantially of the same frequency of the THz spectral range between the equidistant neighboring subbands, whereby an application of an external bias field across the first and second layers causes the THz spectral range radiation originating from said radiative transitions of non-equilibrium carriers between at least one of the following: neighboring energy subbands of the EQW, neighboring energy subbands of the HQW, and ground energy electron subband of the EQW and ground energy hole subband of the HQW.