Excitation Spectra of Arsenic and Antimony Impurities in Germanium under Uniaxial Compression

The stress-induced splittings of spectral lines arising from both the triplet and singlet ground states of arsenic and antimony impurities in germanium have been observed. In the case of arsenic impurity, the effect of compression along $〈111〉$ has been studied, while for antimony, compression along both $〈111〉$ and $〈110〉$ has been used. The spectra have been examined with the use of polarized radiation. Price's calculations regarding the behavior of donor states under stress have been compared with the positions of the stress-induced components of the excitation lines and are well substantiated by the experimental results. Because of the relatively small chemical splitting of the ground states of antimony impurity, the high-stress asymptotic limits are reached for its excitation spectrum under stress. The predicted stress dependence of the relative intensities of the excitation lines of both impurities are consistent with those observed experimentally.