Temperature induced stress of ZnSe quantum dots in glass matrix thin films grown by pulsed laser deposition

Abstract

By analyzing the temperature dependent spectral shifts and broadenings of both photoluminescence (PL) and Raman modes from the ZnSe-doped glass thin films grown by pulsed laser deposition, we found that temperature induced stress causes excess shifts of the PL emission bands to higher energies when the samples were kept below 100K. The compressed stress may be a result of the different thermal expansion of the ZnSe nanocrystal and the glass matrix; it is further confirmed by the temperature dependent excess Raman shift in this quantum dot sample as compared with the crystal data in the high-pressure experiment. In addition, we found the activation energies of the nonradiative decay channels associated with the edge-emission and deep-level bands are close to 1TO and 1LO of ZnSe phonon energies.