Theory of radiative recombination from the metastable excited states of quantum dots

The radiative recombination of an exciton ~electron-hole pair! confined in a semiconductor quantum dot is studied within a general model based on the effective-mass approximation. The dependence of the photoluminescence spectrum on the size of the dot and the magnetic field describe well a series of recent experimental results. In particular, a characteristic splitting of the main photoluminescence peak into a doublet or triplet is observed at the critical size and magnetic field, as a consequence of the appearance of metastable states in the exciton spectrum. @S0163-1829~98!06915-X#