X-ray emission from core excitons

Abstract

We have observed soft x-ray emission from core excitons in several semiconductors and insulators and find that the exciton intensity is related to its binding energy. We propose an explanation for these excitons and this relationship using a Wannier model. The validity of the Wannier model is further tested by comparing our measured exciton binding energies with predicted values. We conclude that this model appears to be a good starting point in the understanding of core excitons.