The Influence of the Dynamic Jahn-Teller Effect on the Phonon-Scattering Mechanism at Acceptors in Semiconductors with Cubic Symmetry

The ground state of acceptors in cubic semiconductors is fourfold degenerate (I?,) and the interaction with the lattice vibrations leads to the possibility of a Jahn-Teller effect [l]. The extended nature of the wave function of these defects [ 2 ] has two important consequences : (i) the interaction is mainly with long-wavelength acoustic phonons, (ii) because of the large elastic energy associated with the center and the small Jahn-Teller energy residual static strains may destroy the Jahn-Teller effect. There is a series of phonon experiments [3 to 61 and optical measurements [7, 81 which indicate a resonance energy in the meV range for the deeper acceptors GaAs (Mn), GaP(Zn), &(In), and Si(B). These energies are much larger than the splitting due to random internal fields, which are of the order of 10 to 100 peV in these crystals. In the following we want to show that these resonance energies are related to the dynamic Jahn-Teller effect. The acceptor-hole-lattice interaction Hamiltonian can be written in the form