Interface Recombination Reduction by (NH₄)₂Sx-Passivation in Metalorganic Chemical Vapor Deposition Regrown GaAlAs/GaAs Buried Heterostructure Lasers and Estimation of Threshold Currents in Microcavity Surface Emitting Lasers

Ammonium sulfide [(NH 4 ) 2 S x ] treatment has been applied to a metalorganic chemical vapor deposition (MOCVD) regrowth process for GaAlAs/GaAs buried heterostructure (BH) lasers to reduce the nonradiative interface recombination. A mirrorlike Ga 0.9 Al 0.1 As layer was successfully grown on Ga 0.7 Al 0.3 As by introducing sulfur treatment before regrowth. The interface recombination velocity along the side wall of the active region was significantly reduced. This fabrication technology is expected to be effective in the realization of ultralow-threshold microcavity lasers.