Abstract
To analyze the main features of THz radiation generation caused by optical-phonon transit-time resonance in the case of bidimensional transport, a simplified analytical model is developed in terms of generalized parameters of bulk materials and 2D structures. In the framework of such a model and direct Monte Carlo simulations, it is shown that for a given material: (i) the generation conditions are the same in quantum wells and heterolayers, and they can be characterized by the same parameter related to the effective width of the 2D-channel and with the optical phonon momentum, (ii) a considerable increase up to 5 times of the high-frequency cut-off for THz radiation generation is predicted in going from 3D to 2D transport.