AVS 62nd International Symposium & Exhibition
    Thin Film Thursday Sessions
       Session TF-ThP

Paper TF-ThP13
Influence of Cu Doping on the Electrical Transport Properties of Transparent ZnO Nanocrystalline Films Prepared by Sol-Gel Spin Coating Process

Thursday, October 22, 2015, 6:00 pm, Room Hall 3

Session: Thin Films Poster Session
Presenter: Chung-Yuan Kung, Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan, Taiwan, Republic of China
Authors: C.Y. Kung, Department of Electrical Engineering, National Chung Hsing University, Taichung, Taiwan, Taiwan, Republic of China
S.L. Young, Department of Electronic Engineering, Hsiuping University of Science and Technology, Taichung, Taiwan, Taiwan, Republic of China
H.H. Lin, Department of Electronic Engineering, Hsiuping University of Science and Technology, Taichung, Taiwan, Taiwan, Republic of China
Correspondent: Click to Email

ZnO and Zn0.98Cu0.02O nanocrystalline films were separately deposited on the glass substrates by sol-gel spin-coating technique for the exploration of Cu doping effect. X-ray diffraction patterns of the films show the same wurtzite hexagonal structure and preferential orientation along the c-axis. The grain size of ZnO and Zn0.98Cu0.02O films are 52.3 and 126.4 nm calculated by Scherrer Formula, respectively. The increase of grain size induced by Cu doping result can be also observed by SEM images. Hall mobility and carrier concentration of the p-tpye Zn0.98Cu0.02O films decrease and resistivity increase as Cu doping due to the increase of defects examined by photoluminescence spectra. Temperature dependence resistivity reveals a semiconductor transport behavior for both nanocrystalline films. Exponent relationship σ(T)=σh0 exp[-(T0/T)1/4] at low temperature region and Arrhenius equation σ(T)=σ0 exp[-(Ea/Kt)] at high temperature region are both fitted well, which separately reveals Mott variable range hopping behavior and thermal activation conduction. Activation energy Ea increases from 46 meV for ZnO to 124 meV for Zn0.98Cu0.02O calculated by Arrhenius equation, respectively. The results demonstrate that the crystallization and the corresponding carrier transport behavior of the Zn0.98Cu0.02O films are affected by Cu doping.