Effect of X-ray irradiation on CdS1−xSex quantum dots optical absorption

Optical absorption spectra of X-ray irradiated CdS1−xSex quantum dots embedded in a borosilicate matrix are studied. As the irradiation dose is increased up to 3240 Gy, the quantum-size-related maxima are smeared and the absorption edge is blue shifted. The observed effects are related to the X-ray ionization of the quantum dots with charge-carrier transfer between the nanocrystals and the host matrix as well as to the additional hydrostatic pressure upon the quantum dots due to the radiation-induced swelling of the glass matrix. The radiation-induced changes vanish completely at post-irradiation annealing up to 575 K.