Impact of Silver Incorporation and Flash-Lamp-Annealing on the Photocatalytic Response of Sputtered ZnO Films

• Published in: Nanomaterials (Basel, Switzerland) Vol. 14; no. 18; p. 1519
• Main Authors: Álvarez-Fraga, Leo, Gago, Raúl, Calatayud, David G, Prucnal, Slawomir, Sánchez, Olga
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.09.2024; MDPI
• Subjects: Annealing; Chemical composition; co-sputtering deposition; Crystal structure; Crystallization; Crystallography; Efficiency; Energy; Energy gap; Flash lamps; Fossil fuels; Hydrogen production; Light; Magnetic properties; Magnetron sputtering; Morphology; Nanoparticles; optical properties; Photocatalysis; Room temperature; Semiconductors; Silver; silver doping; structural analysis; Thin films; Wurtzite; Zinc oxide; Zinc oxides; ZnO film; co-sputtering deposition; silver doping; ZnO film; optical properties; structural analysis; morphology; photocatalytic activity; methyl orange; flash-lamp-annealing
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano14181519

Thin films of silver-doped zinc oxide (SZO) were deposited at room temperature using a DC reactive magnetron co-sputtering technique using two independent Zn and Ag targets. The crystallographic structure, chemical composition and surface morphology of SZO films with different silver concentrations were correlated with the photocatalytic (PC) properties. The crystallization of the SZO films was made using millisecond range flash-lamp-annealing (FLA) treatments. FLA induces significant structural ordering of the wurtzite structure and an in-depth redistribution of silver, resulting in the formation of silver agglomerates. The wurtzite ZnO structure is observed for silver contents below 10 at.% where Ag is partially incorporated into the oxide matrix, inducing a decrease in the optical band-gap. Regardless of the silver content, all the SZO films do not exhibit any significant PC activity. The best PC response is achieved for samples with a relatively low Ag content (2-5 at.%) after FLA treatment. The enhanced PC activity of SZO upon FLA can be attributed to structural ordering and the effective band-gap narrowing through the combination of silver doping and the plasmonic effect caused by the formation of Ag clusters.