Dr. Yaojun Du
Research Associate
Office:
311 Olin Physical Laboratory
Mail Address:
100 Olin Physical Laboratory
Wake Forest University
Winston-Salem, North Carolina 27109-7507
Telephone: : (336) 758-5337
Fax: (336) 758-6142
E-mail: dyj at mps dot ohio-state dot edu
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Born in Shanghai China, I obtained a B.S. in physics at Shanghai
Jiao Tong University in 1999 and a M.Phil in physics at Hong Kong
University of Science and Technology in 2001. After completing a
Ph.D. in physics with Prof. John Wilkins at Ohio State University
in 2005, I have been working as a research associate at Wake Forest
University. My work relies on the local
high-performance parallel cluster (DEAC)
Research Abstracts
My researches focus on the simulation of real materials using classical potentials,
tight-binding models, and first-principles Density
Functional Theory (DFT). I predicted the structural and
dynamical properties of various defect structures in semiconductor silicon
materials. Also revealed the microscopic mechanism of the
ionic transport in solid state electrolyte materials that can be incorporated
into thin-film Li ion batteries. Moreover, I am interested in devevloping the
DFT method.
- I have dealt with clusters of N interstitial atoms
(IN) in silicon, which are formed following ion
implantation. I extensively studied the potential energy surface
for I2, I3, and I4. Identifying
local minima and the transitions among these minima on these
energy surfaces allows one to obtain a complete understanding of
the low-lying configurations, diffusion pathways and
barriers. Especially, the formation process of some important
structures can be proposed. Previously even for small cluster
scientific knowledge on the energy landscape had been incomplete,
and for larger clusters understanding becomes much more difficult
as larger supercells are needed and the potential energy surface
has exponentially more local minima. As a result, fast energy
landscape search relies on the coupling of efficient landscape
searching scheme and well fitted tight-binding and classical
Hamiltonians. The final identified structures will be examined in
DFT calculations.
- I have also been working on the diffusion process within ionic
materials under development for use in Li ion batteries. Detailed
atomistic diffusion paths and associated diffusion barriers might
help to understand ionic diffusion mechanism in the materials. I
have tried to understand the effects of N and Si dopants on the
ionic transport and local structures in the
Li3PO4-based electrolyte, and representive
atomic structures associated with the LiPON thin films
- UltraSoft PseudoPotential (USPP) and
Projector Augmented Wave
(PAW) method are two DFT pseudopotential schemes allow one to
perform first-principles simulations on hundreds of atoms by
applying low cut-off energies. I am engaged in understanding the
basic connections between the USPP and PAW in order to generate
USPP potentials using the PAW code.
(last revised September 18, 2008)
