Time evolution of ZnO-CNT photoluminescence under variable ambient and temperature conditions

ZnO-CNT hybrid materials were prepared by non-aqueous sol-gel routes at 240ºC. The morphology and defects have been studied by transmission electron microscopy and photoluminescence spectroscopy. The hybrid nanostructures manifest a broad luminescence emission covering the visible spectrum. Variations in photoluminescence with time are observed for the ZnO-CNT hybrid structures exposed to different ambient and temperatures. The studies show that photoluminescence from adsorbed oxygen dominates the emission emanating from other intrinsic defects and also affects the stability of the latter over time. (paper)