Far-Infrared Optical Properties of Quenched Germanium; V. Uniaxial Stress Effects on the SA1 Acceptors

Abstract

Far-infrared absorption spectra of quenched germanium were measured under a uniaxial stress along the <100>, <110> and <111> crystallographic orientations. It is concluded from the analyses of the number of the bands split with stress and from the feature of splitting of each band that the SA1 acceptor, which is the shallowest one in the quenched-in acceptors and has a ground state split into two levels without a uniaxial stress, is constructed from a defect in which the symmetric axis is along a <111> crystallographic axis. From the comparison between the results on the SA1 acceptors and the SA1Au and SA1Ag acceptors which are the perturbed SA1 acceptors, it is proposed that the SA acceptor is constructed from a pair of substitutional and interstitial atoms along the <111> axis and that SA1Au and SA1Ag acceptors are the defects consisting of the SA1 acceptor together with either Au or Ag impurities along the <111> axis, respectively.