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.