Terahertz radiating device based on semiconductor coupled quantum wells

A semiconductor device operable in THz spectral range, the device comprising a heterostructure including at least first and second semiconductor layers and al electrodes' arrangement providing electrical contacts to the first and second layers to apply a bias field across them, wherein

• the first and second layers are made of materials providing a quantum mechanical coupling between an electron quantum well (EQW) in the first layer and a hole quantum well (HQW) in the second layer, and providing an overlap between the valence band of the material of the second layer and the conduction band of the material of the first layer,
• a layout of the layers of the heterostructure and potential profiles of the EQW and HQW are selected so as to provide a predetermined dispersion of energy subbands in the conduction band of the first layer and in the valence band of the second layer to define a desired effective overlap between the energy subbands of said conduction and valence bands, said predetermined dispersion resulting in that the application of the external bias field across the first and second layers causes the THz spectral range radiation originating from a resonance condition of radiative transitions of non-equilibrium carriers between the neighboring energy subbands of the EQW, the neighboring energy subbands of the HQW, and the ground energy subbands of the EQW and HQW.

A method of fabricating a semiconductor device operable in a THz spectral range, the method comprising forming a heterostructure from selected layers

• wherein the layers include at least first and second semiconductor layers made of materials providing a quantum mechanical coupling between an electron quantum well (EQW) in the first layer and a hole quantum well (HQW) in the second layer and providing an overlap between the valence band of the second layer and the conduction band of the first layer,
• a layout of the layers of the heterostructure is selected so as to provide a predetermined dispersion of energy subbands in the conduction band of the first layer and the valence band of the second layer to define a desired effective overlap between the energy subbands of said conduction and valence bands, the predetermined dispersion being such that application of a bias field across the first and second layers results in generation of THz radiation originating from a resonance condition of radiative transitions of non-equilibrium carriers between the neighboring energy subbands of the EQW, the neighboring energy subbands of the HQW, and the ground energy subbands of the EQW and HQW.

The method of fabricating a semiconductor device operable in a THz spectral range, the method providing for improved temperature characteristics of the device and comprising forming a heterostructure from selected layers

• wherein the layers include at least first and second semiconductor layers made of materials providing a quantum mechanical coupling between an electron quantum well (EQW) in the first layer and a hole quantum well (HQW) in the second layer and providing an overlap between the valence band of the second layer and the conduction band of the first layer,
• a layout of the layers of the heterostructure is selected so as to provide a predetermined dispersion of energy subbands in the conduction band of the first layer and the valence band of the second layer to define a desired effective overlap between the energy subbands of said conduction and valence bands, the predetermined dispersion being such that application of a bias field across the first and second layers results in generation of THz radiation originating from a resonance condition of radiative transitions of non-equilibrium carriers between the substantially parallel and equidistant neighboring energy subbands of the EQW, the neighboring energy subbands of the HQW, and the ground energy subbands of the EQW and HQW.

The method of fabricating a semiconductor device operable in a THz spectral range, the method providing for improved radiative characteristics of the device and comprising forming a heterostructure from selected layers

• wherein the layers include at least first and second semiconductor layers made of materials providing a quantum mechanical coupling between an electron quantum well (EQW) in the first layer and a hole quantum well (HQW) in the second layer and providing an overlap between the valence band of the second layer and the conduction band of the first layer,
• a layout of the layers of the heterostructure is selected so as to provide a predetermined dispersion of energy subbands in the conduction band of the first layer and the valence band of the second layer to define a desired effective overlap between the energy subbands of said conduction and valence bands, the predetermined dispersion being such that application of a bias field across the first and second layers results in generation of THz radiation originating from a resonance condition of radiative transitions of non-equilibrium carriers between the substantially parallel and equidistant neighboring energy subbands of the EQW, the neighboring energy subbands of the HQW, and the ground energy subbands of the EQW and HQW.