A model of photoinduced annealing of intrinsic defects in hexagonal CdSxSe1−x quantum dots

Abstract

A possible mechanism of photoinduced annealing of intrinsic defects in quantum dots with a hexagonal crystal structure is justified on the basis of the studies of the kinetics of photoinduced decay of luminescence of CdSxSe1−x quantum dots synthesized in a glass matrix and ab initio calculations of chemical bond energies at the interface in the n(CdSe)-SiOx-type cluster. The model proposed implies that photoinduced Se-O bond breaking at the anionic face results in an increase in electric field inside the quantum dot; this field stimulates cadmium vacancy diffusion to the surface. This model accounts for the degradation of luminescence and of the parameters of nonlinear optical devices observed during photoinduced annealing.