Electroluminescence from double-barrier resonant-tunnelling structures

We have performed a theoretical analysis on bipolar double-barrier resonant-tunnelling structures using a two-band model, by solving eight equations self-consistently: the Poisson equation, two Schrodinger equations, four equations for quantum transport of electrons and holes, and the equation for electron-hole radiative recombination. All physical parameters are calculated from first principles, except the electron-hole recombination time tau, which is treated as an empirical parameter. We have investigated in detail the physical processes relevant to the three conditions for optimizing a bipolar double-barrier resonant-tunnelling light-emitting diode: (1) the charge carriers are entirely trapped in the well as the only light source, (2) electrons and holes tunnel resonantly into the quantum well simultaneously and (3) in the well it is nearly zero field. We have studied the electroluminescence spectrum within a wide temperature range and investigated the origin of its temperature dependence. Finally, we consider tau as a varying parameter, to examine the dynamical aspects of the electroluminescence spectrum.