Anomalies in the pressure response of the Raman modes in (211)-oriented InxGa1−xAs/GaAs strained-layer superlattices

Abstract
The phonon spectra of InxGa1−xAs/GaAs strained‐layer superlattices grown on (100), or either one of the two inequivalent (211)A and B surfaces of GaAs were obtained by Raman scattering for pressures ranging from 1 atm to 13.0 GPa. The measurements show that phonon frequencies are discontinuous functions of pressure for (211)A superlattices in contrast to the continuous behavior observed for (100) and (211)B‐oriented superlattices. These discontinuities are discussed in terms of pressure induced increase in the density of heterointerface dislocations.