Local approach to polarizabilities and trends in the Raman spectra of semiconductors

The Raman spectra of several II-VI and III–V compounds are well described with one parameter, namely the ratio of non-linear intra-ionic polarizabilities of the individual ions. This approach is justified by the open-shell electronic configuration of the compounds and is based on a simple overlap shell model which reproduces the phonons in many binary compounds. The relations to bond polarizabilities and the anomalous case of oxides are discussed.