Professor Robert Taylor

Abstract:

Luminescence has been quite widely used for the study of semiconductor nanostructures, and more especially time resolved luminescence, due to the ease to get a luminescence signal. The interpretation of the results however is sometimes quite complex, and one generally finds that some care has to be taken for the results to be meaningful. In particular, the homogeneity of the excited density over the detected luminescence signal is a quite important parameter, also it is often desirable to work at the lowest possible densities.

Abstract:

We present results of time-resolved luminescence experiments performed on Zn0.80Cd0.20Se/ZnSe quantum well laser structures as a function of carrier density and temperature. It is found that in narrow wells, where quantum confinement effects are strong, the luminescence is excitonic over all temperatures at densities up to and above threshold. For wide wells the luminescence is observed to cross over to a bimolecular decay profile at high temperature and density, which corresponds to the formation of a correlated electron-hole plasma.