700-1400 nm Near Infrared Ray Annealing Effects on Spin Coated In doped AZO Thin Films for Transparent Conducting Oxide Applications

초록

Near Infrared Ray (NIR) annealing effects on the material properties of In doped AlZnO (AZO) thin films prepared by spin-coating technique were carried out for transparent conducting oxide applications. For the NIR annealing process, halogen-tungsten lamp was employed to produce wavelength of 700-1400 nm. The crystal structures, electrical and optical properties of In doped AZO films were analyzed, by employing X-ray diffraction, four-point probe and UV-VIS spectrophotometer. The films showed a hexagonal wurtzite structure, and preferential c-axis orientation. The stress of deposited In doped AZO film was decreased as increasing the NIR energy efficiency. The SEM analysis showed that the microstructure becomes densed and grain size was increased as increasing the NIR energy efficiency. The optical transmittance spectra of the films showed higher transmittance more than 85%, within the visible wavelength region. A minimum sheet resistance of 0.6 K Omega/sq was obtained after the NIR annealing process. Also the carrier concentration and mobility were enhanced as increasing the NIR energy efficiency. The optical band gap energy calculated through the transmittance data increased from 3.27 to 3.29 eV, as the NIR energy efficiency increased from 50 to 80%. NIR annealing process seems to be effective method for the transparent conducting oxides thin film applications.

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