Light-current curve of a tunneling-injection quantum dot laser

Abstract

The potential for high-power operation of a laser exploiting tunneling-injection of electrons and holes into quantum dots (QDs) from two separate quantum wells (QWs) is studied. An extended theoretical model is developed to account for out-tunneling leakage of carriers from QDs. Even in the presence of out-tunneling from QDs, the parasitic recombination flux outside QDs is shown to remain restricted with increasing injection current; correspondingly, the LCC becomes more and more linear and the slope efficiency closer to unity at high injection currents. The linearity is due to the fact that the current paths connecting the opposite sides of the structure lie entirely within QDs - in view of the threedimensional confinement in QDs, the out-tunneling fluxes of carriers from dots are limited.