Sidewall Recombination Velocity in GaInAsP/InP Quantum-Well Lasers with Wire-like Active Region Fabricated by Wet-Chemical Etching and Organo-Metallic Vapor-Phase-Epitaxial Regrowth

We estimated the nonradiative recombination velocity at the sidewall of GaInAsP/InP quantum-well lasers with narrow wire-like active region, which had been fabricated by wet-chemical etching and two-step organo-metallic vapor-phase-epitaxial (OMVPE) regrowth, from the active region width dependence of spontaneous emission efficiency under current injection. It was shown theoretically that this estimation method of the nonradiative recombination velocity is more accurate than a conventional method using threshold current dependence on the width of an active region, and was confirmed experimentally. The sidewall recombination velocity of 5 stacked multiple-quantum-well and a single-quantum-well structures fabricated by wet-chemical etching and OMVPE regrowth method was estimated to be 1.3 ×10 3 cm/s and 2.0 ×10 3 cm/s, respectively, at room temperature, while it was estimated to be very small (less than 10 cm/s) at low temperatures ( T = 90 K).