Tailoring Local Conductivity by the Formation of Ag Nanoclusters in SiO2 Xerogel Films

<p>Porous silicon dioxide thin films were produced via dip-coating and doped with Ag+ by adding AgNO3 to the dipping solution. Nanoparticles were formed within the pores of these films by UV exposure. Nanoparticle formation was confirmed by UV-visible spectroscopy and Transmission Electron Microscopy (TEM). Conductive Atomic Force Microscopy (CAFM) showed that the conductivity of the films decreased upon exposure to UV. This decrease in the conductivity is most likely due to the clustering of charge carriers. Initially, Ag+ ions are attached to negatively charged pore walls in a dense packing network. Upon UV exposure (125 mW @ 266 nm), the Ag+ ions are reduced to Ag metal and agglomerate to form clusters. The agglomeration creates gaps in the film that decrease its conductivity. This ability to tune film conductivity was used to create insulating patterns within conducting films. A calibration mask was placed over the films during UV exposure, and exposed regions with a minimum width of ~2 μm were detected as depressions with insulating behavior. The fabrication of photonic and plasmonic devices is being explored using this method.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Physics

Year dc:date.available

2009

Author dc:creator

• Caperton, Ricky

Contributors dc:contributor

• Massimo Bertino

• xerogel
• thin film
• UV exposure
• silver
• Physical Sciences and Mathematics
• Physics

Statement dc:rights

• © The Author

Identifier

https://scholarscompass.vcu.edu/etd/15

OAI identifier oai:identifier

oai:scholarscompass.vcu.edu:etd-1014