Reported by Megawati Omar, Research Management Institute, UiTM
Researchers Mohd Zainizan Sahdan, Mohd Hafiz Mamat, Zuraida Khusaimi, Mohd Noor and Mohd Rusop Mahmud of the Faculty of Electrical Engineering and the Faculty of Applied Sciences, UiTM invented a method to obstruct gas flow in the 2-furnace CVD system to synthesize ZnO nanowires. ZnO nanowires can be synthesized using 2-furnace chemical vapour deposition (CVD) system but the gas flow is an important parameter for the nanowire synthesis as it is challenging to deposit ZnO nanowires it.
These researchers invented and placed a gas blocker at the end of the precursor furnace to obstruct the gas flow. Argon gas with ZnO vapour would hit the gas blocker and it would flow back to the opposite direction. Since Argon gas flowing from left was stronger, with a gold catalyst, it would repel to flow back onto the glass substrate. ZnO microball then would be formed and due to high energy, ZnO nanowires grew on the ZnO microball. High density of ZnO nanowires were synthesized by the gas blocker in the Catalytic Thermal CVD.
In the experiment, this gas blocker controlled a better flow of gas. ZnO nanowires on ZnO microballs were deposited on a glass substrate with high density and repeatability. The Ultra Violet-Visible (UV-Vis) spectrometer showed that ZnO nanowires had high absorption in the UV region which is an important criterion for solar cell applications. The photoluminescence study indicated that ZnO nanowires exhibited a strong excitation in the UV region which is suitable for UV laser diode applications.
Blocking the gas offers a better control of gas flow. Other that that, the fabricated ZnO nanowires has high UV absorption, thus the invention will be useful for light harvesting devices such as solar cells. As ZnO nanowires have strong UV emission, it is also good for light emitting devices such as laser diodes. Lastly, it offers strong impact on the physical and optical properties of ZnO nanowires.
Contact for further information:
