Optoelectronic Properties of ZrO2/Cu/ZrO2 Multilayers Prepared by DC Pulsed Magnetron Sputtering for Electrode and Nano-Filter Applications

Abstract

In this study, ZrO2/Cu/ZrO2 nanostructured multilayers were constructed on glass substrates with diverse Cu interlayer thickness (5–25 nm) employing pulsed DC magnetron sputtering. The optoelectronics and structural characteristics of the multilayer films were reconnoitered. The calculated band gap was reduced from 3.0 to 2.68 eV as the Cu interlayer thickness increased from 0 to 25 nm. The refractive index and coefficient of extinction of ZrO2/Cu/ZrO2 multilayers increased with increasing the Cu interlayer thickness in the visible range. The resistivity recorded a value of 7.29 × 10−3 Ω·cm for ZrO2/Cu (5 nm)/ZrO2 multilayer film while recorded a value of 3.3 × 10−3 Ω·cm for ZrO2/Cu (20 nm)/ZrO2 multilayer film. It was found that the ZrO2/Cu (20 nm)/ZrO2 multilayer film verified the greatest figure of merit value of 3.35 × 10−3 Ω−1 which signifying the best multilayer for transparent conductive film. The ZrO2/Cu/ZrO2 multilayer can be involved as a platform for designing optical nano-filter for molecular detections. For this purpose, the quality factor Q, the FWHM and the optical response of the proposed (ZrO2/Cu/ZrO2)3/Cumid/(ZrO2/Cu/ZrO2)3 optical nano-filter model were calculated theoretically using finite difference time domain technique (FDTD). The quality factor and FWHM of the proposed model recorded values of 5800 and 0.23 nm respectively for Cu mid thickness of 30 nm, which can be potentially engaged as optical nano- filter for molecular detections.