High mobility indium tin oxide thin film and its application at infrared wavelengths: model and experiment.

In this work, high mobility indium tin oxide (ITO) thin films with uniform crystallographic orientation are prepared. These films present a wide-range transmittance window and could be used as transparent electrodes at ultraviolet-visible-infrared wavelengths. In particular, the ITO thin film is characterized by low resistivity (5.1 × 10 Ωcm) and high infrared transmittance (88.5% at 2.5 μm) due to the improved mobility, achieving higher infrared performance than other transparent conductive materials. A model based on carrier's transport theory and Lorentz-Drude dielectric function is proposed to quantitatively calculate the optical performance of conductive thin films under the influence of plasma effect. The calculation demonstrates that ITO is a suitable electrode material for near/middle infrared optoelectronic applications.