Sublattice Displacement Effects in the Electromodulation Spectra of Zincblende‐Type Crystals

Abstract

(a), and H. LANGE (b) Expressions are derived for the deformation potential constants for pure piezomodulation (PM) and piezoelectrically induced linear electromodulation (LER EM), taking into acoount the difference in sublattice displacements caused by strain and field calculated in a previous paper. It is shown that in case of star degeneracy the sublattice contributions to the deformation potential constants C: and Ci differ in LER EM and PM. The theory is applied to the experimental PM and LER EM spectra a t the El, El -+ dl transitions of GaAs reported in the literature. I n agreement with the predictions of the theory, the deformation potential constant CS, extracted from the LER EM data is found to be much greater than that obtained from PM spectra. Es werden Ausdriicke fur die

External and Internal Strains in Piezoelectric Crystals

“…This important fact was demonstrated by Suisky et al [4] and applied to a comparison of electromodulation and piezomodulation spectra in zinc-blende type crystals [5]. Their demonstration followed from a microscopic model specialized to the zincblende point group 43m(T,).…”

“…This quantity is a generalization of the 'internal strain parameter' or 'bond-bending parameter' 5 [5,7,81. The quantity DFa is an internal regime piezoelectric strain.…”