EFFECT OF STRAIN ON CHSH AUGER RECOMBINATION IN STRAINED IN0.53+XGA0.47-XAS ON INP

We calculate the \Conduction, Heavy Hole] -\Split-Off Hole, Heavy Hole] (CHSH) Auger rates in strained In0.53+xGa0.47-xAs on InP, a widely used material system for quantum well lasers. The bandstructure is obtained from an eight-band tight binding model with spin-orbit coupling, strain effects being included via the deformation potential theory. Adding excess In decreases the hole density of states: this effect acts to decrease the Auger rates. The excess In also decreases the bandgap, however, and increases the split-off gap: these effects act to increase the Auger rates. When we include both of these effects we find that the reduction in the net bandgap dominates; hence, the Auger rates increase with excess In for a fixed carrier concentration. We include these Auger rates in the threshold current calculation for a strained layer multi quantum well laser. We find that for x < .15 the strain-induced reduction in the threshold carrier concentration is able to offset the higher Auger rates; thus, the threshold current decreases rapidly with x. For x > .15, however, the threshold carrier concentration changes little and the Auger rates continue to increase; thus, the threshold current begins to increase rapidly with x.