The potential use of spark ablation in development of AgNP decorated copper oxide thin films for photodetection applications

Abstract

Recently, CuO (p-type) semiconductor thin films have been investigated for sensing applications due to their excellent optical properties and narrow bandgap. It has been proposed that the performance of CuO thin films in photosensing applications depends strongly on the grain size, morphology and nanostructure which introduces the possibility of fabricating these materials by spark ablation, a novel, low cost and efficient method capable of producing controlled and clean nanoparticles with various subsequent deposition methods that further broaden the synthesis possibilities. Here we investigated the potential of this method for fabricating photosensing devices through the ability to control the properties of both the deposited copper oxide thin-films as well as nanoparticles of gold. Copper oxide films were obtained on Si wafers by; i) vacuum jet deposition of either Cu or CuxOy layers that were thermally treated to obtain pure CuO phase, ii) spin coating of the Cu or CuxOy nanoparticles (NPs) solution produced by spark ablation which were collected in 2-methoxyethanol. After the CuO nanofilms were obtained, they were decorated with AuNPs by vacuum jet deposition. Phase purity, morphology and particle size were investigated by Grazing Incidence X-ray Diffraction (GIXRD), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM), while optical absorption was determined by UV/Vis spectrometry and photoluminescence spectroscopy (PL). To determine the photocurrent, I/V characteristics were performed both in light and dark conditions. It was determined that produced films show comparable properties with competitive commercial devices.