Localization and thermal escape of excitons in ultrathin ZnSe/ZnS single quantum wells linked to interfacial ZnSe quantum slabs

Ultrathin ZnSe/ZnS single quantum well structures have been grown by molecular beam epitaxy, on GaP substrates with high Miller indices. The optical properties of pseudomorphic ZnSe/ZnS single quantum wells have been investigated by conventional optical methods. Power-dependence and temperature-dependence measurements show that structural disorder plays an important role in ZnSe/ZnS ultrathin single quantum wells. The luminescence emission is the collective response of a group of local potentials with quantum dotlike characteristics. Consequently, the luminescence peak is the convolution of individual narrow lines. In addition, the luminescence spectra are dominated by a thermal escape of carriers when investigating the temperature dependence. © 1998 American Institute of Physics.