Influence of carrier capture on the quantum efficiency of as-etched and epitaxially buried In0.53Ga0.47As/InP quantum wires

Abstract

Using electron beam lithography dry etching and an epitaxial regrowth step we have prepared buried In0.53Ga0.47As/InP quantum wires. Measurements of the quantum efficiency under different excitation energies reveal the strong impact of carrier loss processes in the barrier on the quantum efficiency of the wire structures. For epitaxially buried wires we find under resonant excitation nearly no decrease in the quantum efficiency down to a wire width of 65 nm. This gives evidence that the regrowth step strongly suppresses the nonradiative recombination at the boundaries of the active region of the wire. Furthermore the comparison of resonant and nonresonant excitation yields an improvement of the carrier capture due to epitaxial regrowth.