Mechanism of radiative recombination in the region of interband transitions in Si-Ge solid solutions

The electroluminescence of Si-Ge diodes (with a Ge content of 5.2% in the corresponding solid solutions) in the region of interband transitions has been studied at the temperatures T = 82 K and 300 K. The emission spectra, the linear dependence of the electroluminescence intensity on current, and the exponential decay of the intensity suggest an exciton mechanism of radiative recombination with and without the involvement of phonons during radiative transitions.