 |
Caspar Fall's research
|
|
Summary
I am currently exploring defects in semiconductors, using the ab initio
cluster code AIMPRO. For my PhD, I studied the work functions of metals
from first principles; while for my diploma, I modelled electronic levels
in quantum wires.
Pretty pictures
Ga-core model of a threading screw dislocation in wurtzite GaN.
N atoms shown in blue, Ga atoms in pink.
Ga core atoms are highlighted to show the double helix of Ga-Ga bonds.
The wurtzite [0001] c-axis is in the vertical direction.
Full-core model of a threading edge dislocation in wurtzite GaN.
N atoms shown in blue, Ga atoms in pink.
Core three-fold coordinated atoms are highlighted.
The wurtzite [0001] c-axis is perpendicular to the figure.
Hydrogen atom (white) saturating the dangling bond of a
nitrogen atom (blue) at a gallium vacancy in GaN. Gallium atoms are
shown in red, and the location of the Ga vacancy is indicated by a cross.
By saturating other neighbouring nitrogen dangling bonds, up to four
hydrogen atoms can decorate a gallium vacancy.
Beryllium pair defect at a gallium atom substitutional site
in wurtzite gallium nitride (red: Ga; blue: N; green: Be).
The geometry of this structure was optimised using AIMPRO,
and corresponds to the lowest energy complex
containing two beryllium atoms.
Scientific articles
- Small aggregates of interstitials and models for platelets in diamond,
J. P. Goss, B. J. Coomer, R. Jones, C. J. Fall, C. D. Latham, P. R. Briddon and S. Öberg,
Journal of Physics: Cond. Matt., Vol. 12, No. 49, pp. 10257-10262, December 2000
- Work function anisotropy in noble metals: Contributions from d-states and
effects of the surface atomic structure,
C. J. Fall, N. Binggeli, and A. Baldereschi,
Phys. Rev. B, Vol. 61, No. 12, pp. 8489-8495, March 2000
- Deriving Accurate Work Functions from Thin-Slab Calculations,
C. J. Fall, N. Binggeli, and A. Baldereschi,
Journal of Physics: Cond. Matt., Vol. 11, No. 13, pp. 2689-2696, April 1999
- Study of Electronic States in Hyperbolic Crescent-Shaped Quantum Wires,
C. J. Fall, M.-A. Dupertuis, and E. Kapon,
Optical and Quantum Electronics, Vol. 31, pp. 201-213, March 1999
- Anomaly in the Anisotropy of the Aluminum Work Function,
C. J. Fall, N. Binggeli, and A. Baldereschi,
Phys. Rev. B, Vol. 58, No. 12, pp. R7544-R7548, September 1998
- General Solution Scheme for Second-Order Differential Equations:
Application to Quantum Transport,
M. Di Ventra and C. J. Fall,
Computers in Physics, Vol. 12, No. 2, pp. 248-253, May-June 1998
- Optical Spectroscopy of Semiconductor Quantum Wires,
D. Y. Oberli, F. Vouilloz, M.-A. Dupertuis, C. J. Fall, and E. Kapon,
Nuovo Cimento D, Vol. 17D, No. 11, pp. 1641-1650, November 1995
Caspar Fall email: C.J.Fall@exeter.ac.uk
University of Exeter phone: +44 (1392) 264198
Exeter EX4 4QL, UK fax : +44 (1392) 264111
13th October 1999