Electron-beam-pumped AlxGa1–xSb semiconductor laser

Stimulated emission from Al_xGa_1–xSb solid solutions, excited by an electron beam and cooled with liquid nitrogen, was observed for the first time. This emission was observed throughout the direct-gap range of compositions and the emission wavelength was within the range 1.1–1.6 μ. The dependence of the forbidden-band width E_g on the solid-solution composition x was determined and the point of transition from the direct- to the indirect-gap structure was found (x_c ≈ 0.25, E_gc ≈ 1.145 eV). A discrepancy between the experimental results and a graphical determination of the dependence E_g(x) was due to the influence of donor levels (E_d ≈ 20 meV) below the indirect L minimum. The parameters of a sealed electron-beam-pumped laser made of such a material were determined.