Characterization of ZnO and ZnO:Al thin films deposited by the sol-gel dip-coating technique

THIN SOLID FILMS

卷:517

Article

Marotti, R. E.¹  Bojorge, C. D.²  Broitman, E.³  Canepa, H. R.⁴  Badan, J. A.¹  Dalchiele, E. A.¹  Gellman, A. J.³ 

[1] Univ Republica, Fac Ingn, Inst Fis, Montevideo 11000, Uruguay

[2] CINSO, CITEFA, REPSOL YPF, Buenos Aires, DF, Argentina

[3] Carnegie Mellon Univ, Dept Chem Engn, Pittsburgh, PA 15213 USA

[4] Consejo Nacl Invest Cient & Tecn, CITEFA, CINSO, RA-1033 Buenos Aires, DF, Argentina

关键词: Zinc oxide;    Optical properties;    Doping;    Thin films;    Sol-gel;    Temperature programmed desorption;   

DOI  :  10.1016/j.tsf.2008.06.028

来源: Elsevier

【 摘 要 】

Nanocrystalline zinc oxide films have been obtained by the sol-gel process. The films were deposited from precursor solutions by dip-coating on quartz substrates, and subsequently transformed into nanocrystalline pure or aluminium-doped ZnO films after a thermal treatment. The film microstructure and composition characterization Was Studied by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The optical properties were studied by transmittance spectroscopy. The water adsorption energy was measured by temperature programmed desorption (TPD) in the range 90-700 K. The optical transmittance in the UV region gives bandgap energy values of 3.27 eV for undoped samples, and higher than 3.30 eV for the Al-doped ones. The increase in bandgap energy in Al-doped samples may be explained by band-filling effects. The band edge absorption coefficient increases monotonically for the Al-doped samples but has a shoulder for the undoped ones, which may be assigned to room-temperature excitonic absorption. (C) 2008 Elsevier B.V. All rights reserved.

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