Stress‐Dependence of the Raman Frequencies and Elastic Constants of Cubic Semiconductors

A model proposed by Keating to describe the second‐ and third‐order elastic constants of diamond‐structure crystals is used to calculate the parameters (p, q, r) which characterise the stress‐induced shifts and splittings of k = 0 optical phonon frequency. The results for Si and Ge are in good agreement with experiment. If the electrostatic contributions to the elastic constants and Raman frequencies are neglected, the model may be applied to zinc‐blende‐type crystals, but the results obtained in this way for GaAs and InSb are less satisfactory.