Electronic structures and isomer shifts of Ge, Sn and Sb impurities in elemental semiconductors

Abstract

The electronic structures of substitutional Ge, Sn and Sb as well as tetrahedral interstitial Sn impurities in diamond-structured Si, Ge and alpha Sn hosts are calculated self-consistency with the linear-muffin-tin-orbital Green function method. Experimental isomer shifts are discussed in terms of host and impurity characteristics. The most important parameter determining the isomer shift is the host specific volume. For the substitutional impurities the p-charge cloud is more compressed in the denser hoists. This leads to lower isomer shifts through the enhanced shielding of the s partial wave. The narrow 13.3 keV 73Ge Mossbauer transition is calibrated leading to a value of the relative nuclear radius change of Delta R/R=1.7*10-3.