ELECTRONIC-STRUCTURE AND CORE EXCITONS IN ALSB AS STUDIED BY SOFT-X-RAY SPECTROSCOPY

The A1 K-beta x-ray-emission and the A1 K x-ray-absorption spectra in single crystalline AlSb are reported. A core exciton is observed 0.2 eV below the onset of the Al 1s-to-conduction-band transition. Its intensity is markedly lower than that of the Al 2p exciton in the same compound. This points towards strong dipole selection rules for the formation of core excitons. The corresponding core-exciton recombination radiation could not be identified in the A1 K-beta spectrum. Structure in the emission and absorption spectra are discussed in terms of the one-electron densities of states. From all available experimental data, an empirical density of valence states is constructed for AlSb.