Effects of surface potential on growth of ZnO nanorod arrays investigated by electric force microscopy

The electric and Kelvin force probe microscopy were used to investigate the surface potentials on the ZnO seed layer, which shows a remarkable dependence on the annealing temperature. The optimum temperature for the growth of nanorod arrays normal to the surface was found to be at 600 degrees C, which is in the range of right surface potentials and energy measured between 500 degrees C and 700 degrees C. We demonstrated from both electric and Kelvin force probe microscopy studies that surface potential controls the growth of ZnO nanorods, illustrating the fact that this is a promising technique to visualize the control of ZnO nanorod arrays by studying their surface potentials. This study will provide important understanding of growth of other nanostructures.

Surface plasmon resonance in CdSe semiconductor coated with gold nanoparticles

We have grown CdSe semiconductor films on glass substrates and the films were coated with Au nanoparticles of 10 nm in size by the pulsed-laser deposition technique. The films demonstrate a large enhancement of Raman intensity and photoluminescence of CdSe semiconductor via excitation of surface plasmon resonances in proximate gold metal nanoparticles deposited on the surface of CdSe film. These observations suggest a variety of approaches for improving the performance of devices such as photodetectors, photovoltaics, and related devices, including biosensors.

Influence of doping rate in Er3+:ZnO films on emission characteristics

High-quality Er(3+):ZnO films were grown by the pulsed-laser deposition technique for 0.5 and 2 wt. % Er doping. Two peaks were observed at approximately 1.54 microm in the photoluminescence spectra of samples with 2 wt. % doping contrary to only one peak in the 0.5 wt. % doped sample. Both peaks were found to be strongly temperature dependent. The microscopic studies clearly illustrate that the appearance of the additional peak is attributed to the environment of Er(3+) ions in the form of ErO(6) clusters, which are optically active centers in the ZnO matrix. These results are very important for designing waveguides for telecommunications.