AVS 52nd International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP16
Influences of the Dopant Concentration and Thermal Treatment on Optical and Electrical Properties of C-oriented Aluminum-Doped Zinc Oxide Films

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Aspects of Thin Films Poster Session
Presenter: W.-C. Chen, National Taiwan Normal University, Taiwan
Authors: S.-Y. Kuo, National Applied Research Laboratories, Taiwan
W.-C. Chen, National Taiwan Normal University, Taiwan
C.Y. Su, National Applied Research Laboratories, Taiwan
C.-P. Cheng, National Taiwan Normal University, Taiwan
Correspondent: Click to Email
Transparent and conductive Al-doped zinc oxide (ZnO:Al, AZO) thin films with highly preferential c-axis orientation have been prepared by the sol-gel technique. Structural, electrical and optical properties were performed by XRD, AFM, SEM, four-point probe, photoluminescence (PL) and UV-VIS transmission measurements. The influence of dopant concentration and thermal treatment on the microstructure as well as on the electrical and optical properties of the thin films is investigated. It was found that the FWHM of XRD patterns reach a minimum at annealing temperature of 750 @super o@C, which is consistent with the results of SEM images. Room-temperature PL spectra show two main peaks centered at about 380 nm (UV) and 520 nm (green). The variation of UV-to-green band emission was greatly influenced by annealing temperatures. The minimum sheet resistance of 10@super 5@ @ohm@/sq. was obtained for the film doped with 2 wt.% Al, annealed at 650 @super o@C. Meanwhile, all AZO films are very transparent, between 85 and 95 % transmittance, within the visible wavelength region. The optical absorption edge was found to blueshift with increasing doping concentration as well. Possible causes to the above will be given and discussed. These results indicate that AZO thin films might be a promising candidate for future photonic applications.