The Growth and Characterization of GaN Nanowires
Final rept. 1 May 1998-31 Oct 2001
HOWARD UNIV WASHINGTON DC DEPT OF ELECTRICAL ENGINEERING
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In conclusion, a series of experiments has been performed to optimize the growth conditions for GaN nanowires. A systematic study of the effects of growth parameters on the shape and size of crystal products reveals important information. A growth map with a wider range of experimental parameters can thus be proposed. The map has three distinct zones. The shape and the size of the products in every zone depend on temperature, NH3 flow rate and GaN crystal structure, if the growth time is fixed to be three hours. An effective surface diffusion length comprises Ca surface diffusion length and the anisotropy of the Ga surface diffusion length. An striking feature of the investigation is that, if the growth rate is introduced into a growth model all observed results can be successfully explained. The optimal growth parameters have been determined. One remarkable observation is the formation of nanowires with uniform diameter, of clear crystal structure, an of length larger than 1 mm. For them, the location distribution is uniform and the yield is quite high. The growth map, developed for the first time, to our knowledge, gives a clear direction of how to accomplish nano-or micro products in 1-, 2-, and 3D. It is indeed exciting.
- Physical Chemistry
- Optical Detection and Detectors