Decoração de nanotubos de carbono de paredes múltiplas com nanocristais semicondutores visando aplicações optoeletrônicas

Abstract

Cadmium Sulfide (CdS) and Copper Sulfide (CuxSy) nanoparticles were successfully grown on Multi-Walled Carbon Nanotubes (MWCNT) via a simple chemical reaction. The CdS-MWCNT samples were produced with different parameters such as temperature and time of the reaction. The samples were characterized with Transmission Electron Microscopy (TEM), Energy-Dispersive Spectroscopy (EDS), Selected Area Diffraction (SAD) and X-ray Diffraction (XRD). The obtained images show that the decoration did happen and EDS spectrums reveals the chemical composition of the samples. The SAD patterns of the CdS-MWCNT samples show that the crystals attached to the MWCNT walls are actually CdS. XRD measurements indicate these samples structure as Zinc Blend type. We identified in the CuxSy sample only one phase of these semiconductor CuS. The XRD pattern and the TEM images indicate the presence of at least one more phase. Thin films were produced by filtration but we couldnt estimate the band gap of the CdS-MWCNT using UV-Vis absorption due to high reflection and scattering. We produced a device based on the junction of both MWCNT-CdS and MWCNT-CUxSy, and preliminary test showed that its electrical properties are light variable.