AVS 53rd International Symposium
    Thin Film Thursday Sessions
       Session TF2-ThA

Paper TF2-ThA5
Electrical Conduction in Pulsed-Laser Deposited As- and Ga-doped ZnO Films

Thursday, November 16, 2006, 3:20 pm, Room 2022

Session: Pulsed Laser Deposition of Thin Films
Presenter: A.K. Pradhan, Norfolk State University
Authors: A.K. Pradhan, Norfolk State University
K. Lord, Norfolk State University
D. Hunter, Norfolk State University
T.M. Williams, Norfolk State University
S. Cherry, Norfolk State University
S.L. Jones, Norfolk State University
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The increasing demand for transparent conducting oxides and p-n junction based-short wavelength light emitting diodes has created a lot of research interest. We report the synthesis of epitaxial As-doped ZnO and Mn-doped (ZnAs)O films by pulsed-laser deposition (PLD) technique. The grain size in (ZnAs)O films decreases from 40 nm to less than 10 nm upon Mn doping, illustrating that Mn acts a potential catalyst creating nanosize grains. Temperature dependent electrical resistance shows metal-insulator (MIT) and metal-semiconductor transitions (MST) at 165 and 115K, respectively, in (ZnAs)O, although Mn-doping suppresses MST completely. Both ionization efficiency of oxygen vacancies and percolation of charge carriers may be responsible for such transitions. In addition, electrical conduction is these films show strong ageing effects related to the conductivity instability in the film. We have also synthesized highly epitaxial conducting Ga-doped ZnO system by the PLD techniques. The films show transmittance more than 85% in the visible region. The films show very high electrical conductivity. The temperature dependent resistivity measurements of these highly conducting and transparent films show several transitions. The extensive results will be presented.