| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2018) | |
| Thin Films | Wednesday Sessions |
| Session TF-WeP |
| Session: | Thin Films Poster Session II |
| Presenter: | Katsuhiro Uesugi, Muroran Institute of Technology, Japan |
| Authors: | K. Uesugi, Muroran Institute of Technology, Japan K. Matsumoto, Muroran Institute of Technology, Japan W. Ikesugi, Muroran Institute of Technology, Japan Y. Nakata, Muroran Institute of Technology, Japan Y. Hoshiyama, Muroran Institute of Technology, Japan K. Obara, Muroran Institute of Technology, Japan H. Fukuda, Muroran Institute of Technology, Japan |
| Correspondent: | Click to Email |
Cu2O is recognized as the most promising p-type oxide semiconductor because of its desirable optical properties in the visible region and high Hall mobility. It has been widely studied for the applications such as gas sensors, solar energy conversion, photocatalyst, and photosynthesis. Although Cu2O films can be synthesized by using chemical- and physical-deposition methods and thermal oxidation of metallic Cu surfaces, nano-microscale modifications on the surfaces are important to improve the surface reaction rate of the photoelectrodes. In this study, the self-assembled growth of Cu2O microwire arrays with dot structures was performed on the sol-gel derived Cu2O films by thermal annealing.
A metal precursor solution was prepared by the mixing of copper (Ⅱ) acetate monohydrate and monoethanolamine in 2-propanol at 50 ºC. After thin films were deposited on glass substrates, they were annealed in the furnace at 270 ºC for 40 min. Cu2O(111) peak was observed by the X-ray diffraction measurement of the samples. A lot of wires spread through from dot structures were observed on the surfaces. A typical structure of the wires was 1.6 μm in width and 200-340 μm in length. The number of the wires was proportional to the circumference of the dot, and 10-100 wires per one dot were formed. Although the wires were isotropically grown from the isolated dot, the wire arrays were formed between neighboring dots. The lateral fusion of the wires did not occur, and the wire grown from the different dots was connected directly and formed the microwire array structures. These results suggest that the surface diffusion of the atoms during the thermal annealing was promoted to the parallel direction of the wires.