Photoluminescence of CdS nanoparticles grown on carbon nanotubes covered by a dielectric polymer layer

Photoluminescence (PL) properties of CdS nanoparticles were studied depending on spacing between the nanoparticles and carbon nanotube (CNT) surface. Using a chemical bath deposition procedure the nanoparticles were grown directly on CNT arrays or arrays covered by a polystyrene layer. The polymer thickness was changed by varying the polystyrene concentration in a solution and the duration of CNT immersing. Transmission electron microscopy and atomic force microscopy were used for estimation of CdS nanoparticle size. An increase in the separation between CdS and CNTs was found to enhance the PL intensity and contribute to the exciton lifetime. PL spectra of CdS nanoparticles grown on a CNT surface and polystyrene layer coating the CNTs.