Temperature dependent resistivity switching in CuxO thin films chemically synthesized from high pressure plasma-deposited copper iodide

Abstract

A facile chemical synthetic method was used to synthesize CuxO thin films on glass substrate via in-situ chemical reaction of CuI thin films in NaOH solution at ambient temperature. CuI thin films were produced by a low-cost plasma-assisted dissociation of the chemical vapor of CuI in acetonitrile (CH3CN) at a pressure of 60 Torr. The prepared CuxO thin films were annealed at various temperatures. The XRD studies unveiled the amorphous character of the CuxO thin films. The SEM images indicated that the surfaces of the films were smooth and smoothness depended on annealing temperature. The EDS studies revealed the presence of huge amounts of C and O with a little amount of Cu in the films which resulted due to the deposition of C produced through dissociation of CH3CN in plasma and O produced from chemical reaction in solution. The optical studies showed that transmittance of the CuxO thin films decreased from that of the CuI thin films and depended on the annealing temperatures. The bandgap of the CuxO thin films decreased with annealing temperature and was in the range of 2.30–2.98 eV. The CuxO thin films exhibited resistivity switching behavior in the first heating-cooling cycle and then the resistivity increased with temperature indicating the metallic behavior. These results are propitious for the application CuxO thin films in solar cells and memristor devices.

Keywords

• CuI
• CuxO
• CH3CN
• HP-PECVD
• Bandgap
• Resistive switching