ELECTROLUMINESCENCE FROM DOUBLE-BARRIER RESONANT-TUNNELING STRUCTURES

We have performed a theoretical analysis on bipolar double-barrier res onant-tunnelling structures using a two-band model, by solving eight e quations self-consistently: the Poisson equation, two Schrodinger equa tions, four equations for quantum transport of electrons and holes, an d 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 paramete r. We have investigated in detail the physical processes relevant to t he three conditions for optimizing a bipolar double-barrier resonant-t unnelling light-emitting diode: (1) the charge carriers are entirely t rapped in the well as the only light source, (2) electrons and holes t unnel resonantly into the quantum well simultaneously and (3) in the w ell it is nearly zero field. We have studied the electroluminescence s pectrum within a wide temperature range and investigated the origin of its temperature dependence. Finally, we consider tau as a varying par ameter, to examine the dynamical aspects of the electroluminescence sp ectrum.