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 °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 ∼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 μA cm−2 and 379 μA 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.

► Synthesis of Au–ZnO nanocomposites by a simple and cost-effective spray pyrolysis technique. ► Effect of Au doping on the structural, morphological, optical, compositional properties of ZnO was investigated. ► Improvement in the photoelectrochemical performance of the Au–ZnO nanocomposite was reported.