Optical absorption of II–VI semiconductor-doped glasses exposed to 7 MeV electron irradiation

• Absorption edge of electron-irradiated II–VI nanocrystals in glass is blue shifted.
• Radiation-induced bleaching bands appear at the position of HOMO–LUMO transitions.
• The reason is charge transfer across the nanocrystal/glass interface.
• The radiation-induced changes depend on the nanocrystal size and composition.

Optical absorption spectra of 7 MeV electron irradiated borosilicate glasses doped with CdS1−xSex, CdSe1−xTex, and Cd1−yZnyS semiconductor nanocrystals were investigated. The observed transformation of the confinement-related features in the spectra is related to irradiation-induced negative ionization of the nanocrystals with charge transfer across the nanocrystal/matrix interface. The dependence of the radiation-induced changes on the nanocrystal size and composition is discussed.