Disorder-enhanced Auger recombination in III-V alloys

Abstract

Auger‐recombination lifetimes of the excess carriers in p‐type III‐V alloys are calculated as functions of the chemical composition. The Auger transition involving the conduction band, the heavy‐hole band, and the spin split‐off band is analyzed. The mixing of an s‐like state into the valence band, which is induced by disorder in alloys, is taken into account on the basis of the tight‐binding picture. It is shown that the disorder effect is especially significant in alloys whose band‐gap energy is small, as in InAs_1−xSb_x. A plot of the lifetime against the chemical composition of GaSb_1−xAs_x shows a prominent valley at the composition, where the band‐gap energy is nearly equal to but a little larger than the spin‐orbit splitting.