[Todos] Seminario INQUIMAE - DQIAQF Miercoles 13 de noviembre 14hs

[andrea en qi.fcen.uba.ar]

Miércoles 13 de noviembre de 2013, 14 hs
INQUIMAE. Aula de seminarios del 3er piso. FCEN, Pabellón II.

Density Matrix Treatment of Optical Properties and Photoconductivity in
Photovoltaic Materials

David A. Micha,
Chemistry and Physics Departments, University of Florida, USA.


Following a brief introduction of methods of Chemical Physics and
Computational Chemistry for many-atom systems, it is shown how reduced
density matrices can be used to describe electronic systems undergoing
dissipative dynamics due to their interaction with a medium. This is
applied to silicon compounds including nanostructured silicon slabs and
quantum dots, containing both metal cluster adsorbates and dopants of
groups III and V. Optical properties include photoabsorption and
photoinduced electronic rearrangement at surfaces. Recent development of a
treatment of photoconductivity in these materials starting from atomic
structure is also described.

Research work partly supported by the National Science Foundation and by
the Dreyfus Foundation of the USA.

Propiedades Opticas y Fotoconductividad en Materiales Fotovoltaicos
Usando Methods de Matriz Densidad

Comenzando con una breve introduccion a metodos de Quimicofisica y Quimica
Computacional para systemas de muchos atomos, se muestra como matrices
estadisticas reducidas pueden usarse para describir systemas electronicos
con una dinamica disipativa debida a interaccion con excitaciones de
energia en un medio.  Esto se aplica a compuestos de Silicio incluyendo
superficies nanoestructuradas y “quantum dots”, conteniendo metales
adsorbidos o dopantes de los grupos III y V. Propiedades opticas incluyen
fotoabsorcion y reagrupacion electronica inducida por luz. Desarrollos
recientes se presentan para tratar fotoconductividad en estos materiales a
partir de su estructura atomica.

Biographical Sketch of David A. Micha

a. Professional Preparation.

Institute of Physics, National University of Cuyo, Bariloche, Argentina,
Lic. Phys. (M.Sc.), 1962

University of Uppsala, Sweden, Physical Sciences (Quantum Chemistry), Fil.
Lic. (Ph.D.), 1965, and Fil. Doktor (D.Sc.), 1966

Postdoctoral Research Associate, Quantum Chemistry Group, University of
Uppsala, Sweden, November 1965-January 1966

Postdoctoral Research Associate, Theoretical Chemistry Institute,
University of Wisconsin, Madison, May 1966-July 1967

b. Appointments

Professor of Chemistry and Physics Emeritus, and Adjunct Professor,
University of Florida, Gainesville, January 2008-present

Head, Physical Chemistry Division, Univ. of Florida, 1999-2004.

Director, Univ. of Florida Center for Chemical Physics, 1982-91.

Professor of Chemistry and Physics, University of Florida, July 1974-Dec.
2007

Associate Professor of Chemistry and Physics, University of Florida,
September 1969-June 1974

Assistant Research Physicist, Institute for Pure and Applied Physical
Sciences and Department of  hysics, University of California, San Diego
(La Jolla), August 1967-August 1969

Selected Professional Activities and Awards.

Fellow, Alfred P. SloanFoundation, 1971-74; Visiting Lamberg Professor,
University of Gothenburg, 1971; U.S. Senior Scientist Award, A. Von
Humboldt Foundation, W. Germany, 1976; Fellow, American Physical Society,
1976; J.I.L.A. Fellow, National Bureau of Standards, 1983; Vicechairman
(1987-88) and Chairman (1988-89), American Physical Society Topical Group
on Few-Body Systems and
Multiparticle Dynamics; Invited scientist, Research Awards Program, A. Von
Humboldt Foundation, W. Germany, 1996 and 1997. Visiting Scientist, NSF
Institute for Theoretical Atomic and Molecular Physics, Harvard University
and Smithsonian Institution, 2000,2001; Visiting Scientist, Ecole Normal
Superieure, Paris, France, 2004,2005, 2007. Visiting Scholar, Institute
for Mathematical Applications, Univ. of Minnesota, 2008.

c. Selected Publications

i) Publications related to modeling of optical properties of materials

1. D. A. Micha, "Density matrix treatment of non-adiabatic photoinduced
electron transfer at a semiconductor surface", J. Chem. Phys. 137, 22A521
(2012)
2. J. J. Ramirez, D. S. Kilin, and D. A. Micha, "Electronic structure and
optical absorbance of doped amorphous silicon slabs", Intern. J. Quantum
Chem. 112, 300-313 (2012)
3. Harvy Freitag, Michael Mavros, and  David A. Micha "Optical Absorbance
of Doped Si Quantum Dots Calculated by Time-Dependent Density Functional
Theory with Electronic Self-Interaction Corrections", J. Chem. Phys. 137,
144301 (2012)
4. Tijo Vazhappilly, Dmitri S. Kilin, and David A. Micha, "Photoabsorbance
and Photovoltage of Crystalline and Amorphous Silicon Slabs with Silver
Adsorbates", J. Phys. Chem. C 116, 25525-25536 (2012)
5. Tijo Vazhappilly, and David A. Micha, "Atomic Modeling of Structural
and Optical Properties of Amorphous Silicon", Chem. Phys. Lett. 570, 95-99
(2013)

ii) Other significant publications

1. D. A. Micha "Density Matrix Treatment of Electronic Rearrangement",
Adv. Quantum Chem.35, 317-337 (1999).
2. D. A. Micha "Time-Dependent Many-Electron Treatment of Electronic
Energy and Charge Transfer in Atomic Collisions", invited Feature Article,
J. Phys. Chemistry 103, 7562-7574 (1999).
3. D. A. Micha, A. Santana, and A. Salam "Nonlinear optical response and
yield in the femtosecond photodesorption of CO from the Cu(001) surface: A
density matrix treatment", J. Chem. Phys. 116, 5173-85 (2002).
4. D. A. Micha and B. Thorndyke "The quantum-classical density operator
for electronically excited molecular systems", Adv. Quantum Chem. 47,
293-314 (2004).
5. D. A. Micha, A. Leathers, and B. Thorndyke, "Density matrix treatment
of electronically excited molecular systems: Applications to gaseous and
adsorbate dynamics", pp.165-194 Quantum Dynamics of Complex Molecular
Systems, eds. D. A. Micha and I. Burghardt (Springer-Verlag, Heidelberg
2007)

d. Synergistic Activities.

Scientific research supported by the National Science Foundation and the
Dreyfus Foundation of the USA. Development of new books in Chemical
Physics, under contract; organization of international conferences and
symposia at national meetings; mentoring of undergraduate students with
support from the Dreyfus Foundation.

e. Collaborators and Other Affiliations.

i) Collaborators .
Dr. Salvador Miret-Artes, National Research Council, Madrid, Spain; Dr.
Irene Burghardt, CNRS Scientist, Ecole Normale Superieure, Paris, France;
Prof. Dmitri Kilin, Univ. of South Dakota

ii) PI's graduate and postdoctoral advisors
Ph.D. advisor: Per Olov Lowdin (Uppsala University). Postdoctoral
advisors: Richard B. Bernstein (Univ. of Wisconsin, Madison) and Keith
Brueckner (Univ. of California, San Diego).

iii) Recent graduate students and postdoctoral scholars.
A graduate student, Robert Hembree, is presently working on his PhD with
the advise of the PI. Dr. Dmitri Kilin and Dr. Tijo Vazhappilly have been
postdoctoral research associates with the PI. Five undergraduate students
have recently been doing research under his guidance: Jessica Ramirez,
Michael Mavros, Harvy Freitag, David Stewart, and Nicolas Vinson. Previous
undergraduate research assistants have been David Arlund, Chris Obara, and
Travis LaJoie.