Electrodynamic properties of aqueous spray-deposited SnO2:F films for infrared plasmonics

• Published in: Optical engineering 2017-03, Vol.56 (3), p.037109-037109
• Main Authors: Peale, Robert E, Smith, Evan, Abouelkhair, Hussain, Oladeji, Isaiah O, Vangala, Shiva, Cooper, Tim, Grzybowski, Gordon, Khalilzadeh-Rezaie, Farnood, Cleary, Justin W
• Format: Article
• Language: English
• ISSN: 0091-3286; 1560-2303
• DOI: 10.1117/1.OE.56.3.037109

Electrodynamic properties of fluorine-doped tin oxide films grown by aqueous-spray-based heterogeneous reaction on heated hydrophilic substrates were investigated with emphasis on applications to infrared plasmonics. These properties were correlated with physical ones such as crystallinity, dopant and electron concentrations, conductivity, and mobility. The degree of crystallinity for the nanocrystalline films increases with F concentration and growth temperature. The F concentration in the films is proportional to that in the starting solution. Electron concentration and Hall mobility rise more slowly with F concentration. At their highest, both F and electron concentrations are ∼2% of the Sn concentration. In more lightly doped films, the electron concentration significantly exceeds the F concentration. The achieved resistivity of the doped films is lower than for undoped SnO2 film by 20 to 750 times. The infrared complex permittivity spectrum shows a shift in plasma wavelength from 15 to 2  μm with more than two orders increase in F concentration.