Temperature-dependent photoluminescence from elemental sulfur species on ZnS nanobelts

We report the experimental study of the temperature-dependent photoluminescence from elemental sulfur species on zinc sulfide nanobelts. The green band emission shows an anomalous blueshift-redshift transition and the half-width undergoes a narrowing-broadening transition with decreasing temperature. We observed that the thermal quenching of the integrated intensity of the green band was suppressed. The anomalous behavior can be attributed to strong carrier localization in the unsaturated dangling orbitals of the elemental sulfur. In addition, the blue band in the undoped ZnS nanobelts is also related to the surface sulfur species that is different from the previously reported self-activation mechanism. (c) 2006 American Institute of Physics.