Quantification and impact of nonparabolicity of the conduction band of indium tin oxide on its plasmonic properties
Doped indium tin oxide (ITO) behaves as a Drude metal with a plasma frequency that is controlled by its free carrier density. In this work, we systematically tune this frequency across the mid-infrared range by annealing treatments in a reducing environment that produce high electron concentrations (∼10{sup 21 }cm{sup −3}). The changes in ITO's optical properties that result from the changes in carrier density are measured by attenuated total reflection measurements. These optical frequency measurements are complemented by Hall measurements to obtain a comprehensive picture of the Drude response of the ITO films. It was found that a complete description of the optical properties at very high carrier densities needs to account for the nonparabolicity of the conduction band of ITO and a reduced carrier mobility. More specifically, an increase in carrier concentration from 6.2 × 10{sup 19 }cm{sup −3} to 1.4 × 10{sup 21 }cm{sup −3} comes with a change of the effective electron mass from 0.35 m{sub 0} to 0.53 m{sub 0} and a decrease in the optical frequency mobility from about 20 cm{sup 2} V{sup −1} s{sup −1} to 9 cm{sup 2} V{sup −1} s{sup −1}.
- OSTI ID:
- 22391894
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Optical properties of amorphous and crystalline Sb-doped SnO{sub 2} thin films studied with spectroscopic ellipsometry: Optical gap energy and effective mass
The change of optical, electrical and structural properties of sputtered indium tin oxide films by application of a new reactive sputter atmosphere