Schmult, Stefan and Keck, Ingo and Herrle, Thomas and Wegscheider, Werner and Bichler, Max and Schuh, Dieter and Abstreiter, Gerhard
Field-effect-induced midinfrared electroluminescence of a quantum-wire-cascade structure by remote d-doping.
Applied Physics Letters 83 (10), pp. 1909-1911.
We present a quantum-cascade emitter in the galliumarsenide/aluminum–galliumarsenide (GaAs/AlGaAs) heterosystem whose emission properties are controlled by an additional electric field perpendicular to the transport direction. In our case, the additional field is established by remote delta-silicon doping, which is also responsible for charge carrier supply. The field originating from the delta-doping gives rise to an in-plane confinement creating a quantum-wire cascade. This field-effect quantum-cascade emitter is realized using the cleaved edge overgrowth method. Radiative electronic transitions between discrete energy levels in coupled quantum wires were calculated for such a structure. Without an additional electric field, no significant transport is observed. With a field applied, midinfrared emission is observed at a peak wave number of 1200 cm–1 with a full width at half maximum of 300 cm–1 for a heat-sink temperature of 20 K. The presented sample is an experimental proposal for a unipolar quantum-wire intersubband laser.