Self-Consistent Calculation of Potential Profile of GaN/AlN Resonace Tunnelling Structures

For resonant tunneling structure with GaN – potential wells and AlN – potential barriers, calculation of internal fields caused by piezoelectric and spontaneous polarization was carried. In the model the effective mass of an electron and a dielectric continuum model using finite difference method self-consistent solutions of the Schrödinger and Poisson system of equations taking into account the contribution of piezoelectric and spontaneous polarizations was found.Based on the found solutions of the Schrödinger and Poisson system of equations for resonance tunneling structure, which functioned as a cascade experimentally realized a quantum cascade detector, calculation of the potential profile and the electron energy spectrum was carried. It was found, that calculated value of detected energy is different from the experimentally obtained not more than 3 %.

Theory of Dynamic Conductivity of Three-Barrier Resonance-Tullel Structure with Two-Photon Laser Transitions

Within the approximation of effective mass and rectangular potential barriers for the electron and using the obtained solutions of complete Schrodinger equation, the theory of dynamic conductivity for three-barrier resonant tunneling structure (InGaAs/InAlAs) with different depths of potential wells driven by weak electromagnetic field is developed in one- and two-photon approach. It is shown that varying Ga concentration one can obtain such geometric configurations of nanostructure, being an active region of quantum cascade laser, in which the increasing intensity of laser radiation, produced by electron quantum transitions accompanied by radiation of two photons with equal energy, is observed. It is established that the contribution of two-photon transitions into the complete magnitude of dynamic conductivity is not smaller than 37 %.