Exciton binding energy and radiation lifetime in CdTe/Cd1−xZnxS strained core/shell spherical quantum dots under pressure.

In this paper, the exciton binding energy and radiation lifetime in type I and II structures of CdTe/Cd 1 − x Zn_xS strained core/shell spherical quantum dots under the hydrostatic pressure have been studied by using the variational method within the continuous dielectric model and effective mass approximation. The results show that for these two structures, the exciton binding energies with and without strain decrease with the increasing core radius but increase with the increasing pressure. The exciton binding energy with strain is smaller than that without strain. For type I structure, the effect of strain is small, and the radiation lifetime decreases monotonically with the increasing pressure. By contrast, for type II structure, the effects of shell radius and strain on the exciton binding energy are obvious, and the radiation lifetime increases first and then decreases with the increasing pressure. [ABSTRACT FROM AUTHOR]