Synthesis, properties and applications of GaN nanowires

Permanent URL: http://hdl.handle.net/2047/d20003131
Title:
Synthesis, properties and applications of GaN nanowires
Creator:
Ma, Zheng (Author)
Contributor:
Menon, Latika (Advisor)
Kar, Swastik (Committee member)
Heiman, Donald (Committee member)
Feiguin, Adrian (Committee member)
Publisher:
Boston, Massachusetts : Northeastern University, 2013
Date Accepted:
April 2013
Date Awarded:
May 2013
Type of resource:
Text
Genre:
Dissertations
Format:
electronic
Digital origin:
born digital
Abstract/Description:
This main focus of the work is on controlling the growth morphology in GaN and related nanowires. Two key results are presented: (1) demonstration of GaN nanowire growth in a newly discovered `serrated' morphology and (2) demonstration of Mn-doped, GaMnN nanowires by a new method. In (1) it is shown that simply by controlling the type of catalyst, size of the catalyst and the initial ratio of the precursor materials, GaN nanowire growth in a highly periodic serrated morphology can be obtained. Unlike regular non-serrated wires which grow in the non-polar [1010] direction, growth of the serrated wires is in the polar [0001] direction. The serrated faces are oriented in the semi-polar directions. Wires with serrated faces in both [1011] and [1122] semi-polar directions have been obtained. In (2) it has been shown that by using Au-Mn alloy catalyst method, GaMnN wire growth can be obtained. This is a significant result since this may be the first demonstration wherein Mn doping is achieved by introducing Mn as a catalyst rather than as a source material. The growth direction of these GaMnN wires is in the non-polar direction as in the case of non-serrated wires. Interestingly, unlike the non-serrated GaN wires, in this case the growth direction is [1120]. A second focus of the work is on the investigation of transport properties of serrated GaN nanowires and comparison with the non-serrated GaN nanowires. For the serrated nanowires our results indicate significant influence of surface effects on the electronic transport resulting in much higher electrical resistivity. A third focus of the work is on the investigation of magnetic properties of the GaMnN nanowires which indicates potential weak ferromagnetic behavior. This is consistent with low hole concentration and low Mn doping concentration (~0.5%) in these nanowires.
Subjects and keywords:
chemical vapor deposition
GaN
nanotechnology
nanowires
semiconductor
Nanotechnology fabrication
Physics
DOI:
https://doi.org/10.17760/d20003131
Permanent Link:
http://hdl.handle.net/2047/d20003131
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