Speaker
Mr
Jatani Ungula
(University of the Free State)
Description
ZnO nanorods (ZRs) were synthesized on glass substrates coated with Ga-doped ZnO (GZO) seed layer by a two-step chemical bath deposition technique (CBD) in an equimolar (50 mM) aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine at 90 °C. The GZO NPs seeding was done to lower the thermodynamic barrier by providing nucleation sites to improve the aspect ratios and optical properties and ensure uniformity of ZRs [1]. The effect of CBD growth times 30, 60, 90, 120, 180, 240 and 320 min on the morphology, luminescence and optical properties of ZRs were investigated. The XRD analysis revealed that the as-grown ZRs have a crystalline hexagonal wurtzite structure and was preferentially oriented along the c-axis. The highest intensity of the (002) peak was observed on the 120 min among the growth durations studied. The SEM micrographs showed that both the length and aspect ratio of the ZRs increased as the growth time increases up to 120 min, then reduced at higher growth times. The photoluminescence measurement spectra depict an enhanced intensity ratio of the UV to visible emissions for ZRs grown on GZO seed layer indicative of high optical quality. The UV-Vis analysis showed that the transmittance of the films was above 80 % and the band gap varied from 3.20 to 3.3 eV with the increase in growth time.The highly transparent film composed of well-aligned ZRs with perfect crystallization produced at the growth time of 120 min can be used as a possible photoanode component in dye-sensitized solar cell.
Reference:
[1] H. K. Lee, M. S. Kim, J. S. Yu, Nanotechnology 22, 445602, 2011.
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
PhD
Summary
ZnO nanorods (ZRs) were synthesized on glass substrates coated with Ga-doped ZnO seed layer by a two-step chemical bath deposition technique (CBD) in an equimolar (50 mM) aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine at 90 °C.The effect of CBD growth times 30, 60, 90, 120, 180, 240 and 320 min on the morphology, luminescence and optical properties of ZRs were investigated.The highly transparent film composed of well-aligned ZRs with perfect crystallization produced at the growth time of 120 min can be used as a possible photoanode component in dye-sensitized solar cell.
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
YES
Apply to be<br> considered for a student <br> award (Yes / No)?
YES
Main supervisor (name and email)<br>and his / her institution
Prof Francis B Dejene
Dejenebf@ufs.ac.za
University of the Free State
Primary author
Mr
Jatani Ungula
(University of the Free State)
Co-authors
Prof.
Francis B Dejene
(University of the Free State)
Prof.
Hendrik C Swart
(University of the Free State)
