DC pulsed plasma magnetron sputtering of CdO/Cu/CdO multilayers thin films for self-cleaning and optoelectronic applications

Abstract

In this study, CdO/Cu/CdO multilayers thin films were organized on glass substrates with different Cu intermetallic layer thickness engaging DC plasma magnetron sputtering. The optoelectronic properties and structural characteristics of the multilayers at various Cu intermetallic layer thicknesses which were varied from 4 to 16 nm were explored. The calculated band gap was reduced from 2.66 eV to 2.48 eV as the Cu intermetallic layer thickness increased from 4 to 16 nm. The refractive index and coefficient of extinction of CdO/Cu/CdO multilayers increased with increasing the Cu intermetallic layer thickness. The resistivity is reduced from 1.8×10−2 Ω.cm for CdO single layer to reach a value of 2.7×10−4 Ω.cm for CdO/Cu (16nm)/CdO multilayer. Further, the sheet resistance is decreased from 1000 to 13.8 /sq with the variation in Cu intermetallic layer thickness from 0 to 16 nm. CdO/Cu (4 nm)/CdO multilayer film recorded the best figure of merit (2.3x10-4 Ω−1). After sunlight illumination for the multilayers, the surface wettability was improved and the contact angle recorded lowest value of nearly 24 for CdO/Cu (8nm)/CdO and CdO/Cu (12nm)/CdO.

Characterization of Different Metal Oxides Thin Films Deposited by Spin Coating Technique

“…Therefore, this construction is suitable for waste water treatment. Abd El-Moula et al [33] developed CdO/Cu/CdO thin film multilayers, applying the DC pulsed plasma sputtering technique, for some optoelectronics self-cleaning applications. Among the used techniques for the thin film fabrication, the sol-gel spin-coating technique has some unique advantages, including the simplicity, low cost, easy adjusting composition, simple deposition equipment, fabricating large-area films, the easy preparation of a homogeneous mixture of two cations in the liquid state, and the non-use of any volatile compounds.…”