Enhancement of Photoluminescence from ZnO Film by Single Wall Carbon Nanotubes

Abstract

Optical emissions from ZnO films were enhanced by a formation of hybrid structures with single wall carbon-nanotubes (SWCNTs). The SWCNTs were characterized by the presence of the associated fibers and islands together with many carbon nanotube structures and their average height was about less than or similar to 40 nm from atomic force microscope and scanning electron microscope measurements. The intensities of photoluminescence on ZnO films with SWCNTs were increased up to about 30 and 60% in the region of 3.3 eV (near band edge) and 2.3 eV (deep-level) bands, respectively. It was considered that the enhancement of optical emissions from ZnO might be resulted from the effects of an excitation light scattering by SWCNTs and a surface plasmon resonance between bandgap of ZnO and SWCNTs. The surface plasmon resonance mode in the ultra-violet regions is smaller than the deep-level region relatively. This result showed that the commercial ZnO/carbon nanotubes have a feasibility of application to optoelectronic device.