Separation dynamics of characteristic X-ray radiation into luminescence and Raman scattering in wide gap insulators

Abstract

Abstract We theoretically study the separation dynamics of luminescence from Raman scattering in the spectral shape of X-ray radiation from a shallow core level to a deep one in wide gap insulators. We employ a four-band model composed of dispersionless deep and shallow core bands, and conduction and valence bands. The effects of the conduction electron-valence hole pair, created by the original electron excited from the deep core level to the conduction band, are taken into account by the lowest order perturbation theory. When the excitation energy is above the absorption edge, the resultant radiation spectra separate into two parts: a luminescence part, and a Raman scattering part peaked in its higher energy side. The condition for luminescence is that the conduction and valence band widths are finite, and the lifetime of the deep core hole is long enough.