Hall measurements of treated indium tin oxide surfaces

We report investigations of the electronic transport properties of indium tin oxide (ITO), thin films on glass carried out by means of the Hall technique. The ITO thin films were studied both as received from a commercial supplier, and after a variety of surface treatments. We find that oxygen-plasma treatments induce a significant increase in the carrier concentration (up to 4.73×1021 cm−3), and a less significant decrease of mobilities (down to 12.3 cm2/V/s) with respect to “as-received” or aquaregia-treated substrates. We attribute this to an increased concentration of defects, as a result of the plasma exposure. The results also suggest that high ITO carrier concentrations may be preferable to high carrier mobilities in order to improve the performance of LEDs with poly(p-phenylene vinylene) active layers.