Growth and properties of multiphase gallium nitride nanowires

PHYS 712

Joshua B. Halpern, jhalpern@howard.edu1, Benjamin W. Jacobs, jacobsbe@gmail.com2, Virginia M. Ayres, ayresv@msu.edu2, Martin A. Crimp, crimp@egr.msu.edu3, Maoqi He, mqhe@msrce.howard.edu4, and Kaylee McElroy, Kaylees@gmail.com2. (1) Department of Chemistry, Howard University, 525 College St. NW, Washington, DC 20059, (2) Department of Electrical and Computer Engineering, Michigan State University, 2120 Engineering Building, East Lansing, MI 48824-1226, (3) Department of Chemical Engineering and Materials Science, Michigan State University, 3513 Engineering Building, East Lansing, MI 48824-1226, (4) Department of Electrical Engineering, Howard University, Washington, DC 20059
Catalyst-free vapor-solid nanowire growth, a newly described method for the production of nanowires compatible with a wide variety of semiconductor materials, has been used to produce novel multiphase zinc-blende/wurtzite gallium nitride nanowires. Multiphase nanowire growth occurred at nanoscale nucleation sites on platelets of gallium nitride. Evidence supports a mechanism where gallium is sourced via a kinetic equilibrium of platelet growth and decomposition, which leads to nanoscale nucleation sites. It is also known that NH3 can undergo a barrierless chemisorption on GaN, leaving NH2 and H with nitrogen incorporation occurring at step edges. Growth temperature has been shown to exert a strong influence on nucleation site formation. Multiphase GaN nanowires may have novel properties that augment and may be superior to single-phase nanowires in device applications. 2-point and 4-point probe current-voltage characterizations were carried in a special nanoprobing system with direct SEM visualization. Evidence for single-phase current transport within the multiphase nanowire structure is discussed.
 

Nanostructured Materials
1:20 PM-5:00 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 338, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008