(Georgia Institute of Technology, 2013-05-08)
Halim, Abigail
In this study, antimony tin oxide (ATO) nanoparticles from Alfa Aesar were redispersed in water using tetramethylammonium hydroxide (TMAH) as a dispersing agent and deposited onto glass substrates by spin coating. Films of one to five layers were made. These thin films were characterized using impedance spectroscopy and ultraviolet-visible spectroscopy to obtain their resistances and optical transmittance, respectively. The films displayed sheet resistances around 10⁵-10⁴ kΩ/ and optical transmittance in the near infrared to near ultraviolet range above 95%. Films were then made using a higher concentration ATO solution and found to achieve sheet resistances on the order of 10 ² kΩ/. Impedance measurements, along with optical micrographs, were taken at different locations on the films, demonstrating that films of more than one layer showed greater uniformity. Further sets of films were also produced with varying substrate preparation and dispersion deposition parameters. Aside from dispersion concentration, high humidity during film measurement was found to be the most crucial parameter for achieving low sheet resistances.