Zinc oxide (ZnO) nanostructures with various morphologies (pencil-like nanorods, nanotubes, and lotus-like structures) have been successfully formed by simple oxidation of vacuum deposited Zn thin film on glass/ITO substrates in hot water at 90 °C. The morphology evolved from pencil-like nanorods to nanotubes to lotus-like structures with prolonged oxidation of Zn thin film for 6–24 h. The change in morphology of ZnO is attributed to the combined effects of electrochemical reactions in the solution, morphology and structure of Zn thin film, and wurtzite structure of resulting ZnO. A hybrid organic–inorganic solar cell following an inverted bulk heterojunction configuration was fabricated based on the lotus-like ZnO structures. The solar cell achieved a power conversion efficiency of up to 1.18%, which demonstrates the applicability of the technique for photovoltaic applications.
Zinc oxide Wet oxidation Hot water Hybrid solar cell Nanostructures
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This study was funded by the Department of Science and Technology under the Engineering Research and Development for Technology and the College of Engineering, University of the Philippines under the Faculty Research Incentive Award and Green Photonics Project of Nara Institute of Science and Technology.
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Conflict of interest
The authors declare that they have no conflict of interest.
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