X-ray study of interface stoichiometry and electronic properties of optically pumped antimonide-based mid-infrared W-laser structures

The authors report on high-resolution X-ray diffraction studies of two antimonide-based mid-infrared W-laser samples. Both samples are of the same layer structure but with different mixed anion interface compositions in order to achieve lattice matching of the active region to the substrate in the second sample. A structural analysis, taking effects into account such as layer relaxation, layer tilting and asymmetrical strain enables an accurate determination of the average lattice constant of the active regions. The authors verify that the aim of lattice matching of the active region in the second sample is clearly achieved, and they also determine the strain values of the W-structure quantum-well layers and estimate the mixed anion interface stoichiometry. With a knowledge of the determined structural parameters, non-radiative recombination processes are investigated with time-resolved photoluminescence as well as laser properties under optically pumped laser operation.