Saturday, January 21, 2017

Abstract-Spectroscopic ellipsometry determination of optical and electrical properties of aluminum doped zinc oxide

  • Department of Physics and Astronomy & Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo, Toledo, Ohio 43606, USA

An aluminum doped zinc oxide (ZnO:Al) thin film is prepared on soda lime glass by radio frequency (RF) magnetron sputtering. Optical properties of ZnO:Al in the form of complex dielectric function (ε = ε1 + iε2) spectra are studied from 0.4 to 6 meV and 0.035 to 5.89 eV using spectroscopic ellipsometry. The film is found to have an optical band gap of 3.62 ± 0.01 eV and an extrapolated DC dielectric constant of 9.072. Resistivity, scattering time, mobility, and carrier concentration are found to be (2.250 ± 0.007) × 10−3 Ω-cm, 5.1 ± 0.7 fs, 20.8 cm2V−1s−1, and 1.3 × 1020 cm−3 respectively. Resistivity and scattering time resulting from fitting to measurements are found to depend on the spectral range modeled, such that the inclusion of increasingly longer wavelengths results in a convergence to direct electrical property measurements

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