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In this paper, Amplified spontaneous emission spectra is used to extract the gain and internal loss of 2.3 μm narrow ridge-waveguide GaInAsSb-AlGaAsSb quantum well laser diodes by Cassidy’s method. The spontaneous emission intensity was extracted using the average value of the amplified spontaneous emission intensity. The dependence of the integrated spontaneous emission intensity on injection current has been studied. The results show that the current is dominated by radiative recombination at this emission wavelength. more...

While nonstoichiometric binary III-V compounds are known to contain group-V antisites, the growth of ternary alloys consisting of two group-V elements might give additional degrees of freedom in the chemical nature of these antisites. Using cross-sectional scanning tunneling microscopy (STM), we investigate low-temperature-grown dilute GaAs1−xPx alloys. High concentrations of negatively charged point defects are found. Combined with transmission electron microscopy and pump-probe transient reflectivity, this study shows that the defects have a behavior similar to the group-V antisites. Further analyses with x-ray diffraction point to the preferential incorporation of arsenic antisites, consistent with ab initio calculations, that yield a formation energy 0.83 eV lower than for phosphorus antisites. Although the negative charge carried by the arsenic antisites in the STM images is shown to be induced by the proximity of the STM tip, the arsenic antisites are not randomly distributed in the alloy, providing insight into the evolution of their charge state during the growth. more...