Spray deposited localized surface plasmonic Au-ZnO nanocomposites for solar cell application

The Au-ZnO nanocomposites were deposited onto the glass and tin doped indium oxide (ITO) coated glass substrates by a simple and cost effective spray pyrolysis technique (SPT) at 450 degrees C. The effect of Au concentration on the properties of ZnO thin films was investigated. The structural evolution of Au-ZnO nanocomposite films with Au doping concentrations is reflected in the X-ray diffraction patterns. The FESEM images reveal uniform and compact distribution of spherical grains/clusters of size similar to 60-80 nm. A clear indication of localized surface plasmon resonance (LSPR) is observed in optical studies. The band gap energy decreases with Au content. The overall photoelectrochemical (PEC) performance of the samples was investigated and discussed. Moreover, the Au-ZnO samples are more photoactive as compare to the pure ZnO sample and the sample ZnOAu15 shows the highest photocurrent. The photocurrent increases up to 279 mu A cm(-2) and 379 mu A cm(-2) in visible light and in UV illumination, respectively. An improvement in the PEC output parameters is observed because of the increased absorption as well as the energy transfer mechanism from the noble metal (Au) to ZnO. (C) 2012 Elsevier Ltd. All rights reserved.