Energy relaxation of an excited electron gas in quantum wires: many-body electron LO-phonon coupling

We theoretically study energy relaxation via LO-phonon emission in an excited one-dimensional electron gas confined in a GaAs quantum wire structure. We find that the inclusion of phonon renormalization effects in the theory extends the LO-phonon dominated loss regime down to substantially lower temperatures. We show that a simple plasmon-pole approximation works well for this problem, and discuss implications of our results for low temperature electron heating experiments in quantum wires.Comment: 10 pages, RevTex, 4 figures included. Also available at http://www-cmg.physics.umd.edu/~lzheng

Influence of Hot Carriers on 1.3 μm InGaAsP Light Emitting Devices

We report the measurement of significant carrier heating in double-heterostructure InGaAsP/InP 1.3 μm light emitting diodes (LED s) and discuss our results in terms of the processes which have been proposed to explain the performance characteristics of LED's and lasers fabricated from this alloy material. In particular, Auger recombination1-3 and intervalence band absorption4 are two mechanisms which have been separately proposed to explain the temperature dependence of threshold and quantum efficiency for lasers and the sublinear output variation with drive current for LED's. A common feature of each of these mechanisms is the generation of hot carriers having an energy of approximately Eg with respect to the band edge (see Fig. 1a). Our results5 demonstrate that indeed hot carriers are being generated and in sufficient numbers to maintain the entire free carrier system at an elevated temperature with respect to the lattice.</jats:p