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Enhancing Optical and Electrical Properties of La- and Al-Codoped ZnO Thin Films Prepared by Sol-Gel Method -La Codoping Effect

[ Vol. 11 , Issue. 2 ]


Hai -Yan He   Pages 146 - 153 ( 8 )


Backgroud: The transparent conductive ZnO film is widely used in solar cell. Enhancing the transmittance and electrical conductivity of the films is attracting many attentions to improve cell efficiency.

Methods: This work focuses on the fabrication and potential application of the various cation-doped ZnO materials in recent patents and literature and then presents the La codoping effects of Al-doped ZnO films. Films were deposited by a sol-gel route and characterized by various techniques including X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, UV-vis and luminescent spectroscopies, and electrical conduction analysis.

Results: The UV-vis. transmittance and band gap increased and then decreased, whereas the resistivity decreased and then slightly increased with the increase in La/Al ratio. The La/Al ratio of 0.0105 led to a maximal transmittance, a widest band gap, and a minimal resistivity. The films also illustrated a near band gap emission and some intrinsic defect-related emissions with varied intensity with La/Al ratio.

Conclusion: This work reveal that the electrical and optical properties of the ZnO:Al films can be well enhanced by La codoping. This is significant to the applications of the ZnO:Al materials.


Codoping effect, microstructure, optical properties, semiconductors, sol-gel chemistry, thin films, ZnO.


College of Material Science and Engineering, Shaanxi University of Science and Technology, Shaanxi

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