Crystallinity and electroluminescence efficiency of CdS nanoparticles grown on the aligned carbon nanotube array

CdS nanoparticles have been grown on multiwalled carbon nanotubes (CNTs) using a chemical bath deposition. Transmission electron microscopy and Raman spectroscopy revealed that crystalline ordering of nanoparticles depends on the duration of synthesis. Moreover, X-ray photoelectron spectroscopy showed that the surface of CdS nanoparticles contains ammonia used as a complexing agent in the reaction. Application of voltage to the substrate with array of aligned CNTs resulted in luminescence of CdS nanoparticles. Efficiency of the electroluminescence depends on the CdS crystallinity and size. Large well-crystallized nanoparticles give bright spots on the cathode image, while the glow from smaller, poor ordered nanocrystalls is strongly scattered. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim