Courses Taught & Under Development
CHE341 Physical
Chemistry I
CHE342 Physical
Chemistry II
CRL 341 Experimental
Physical Chemistry I
CRL 103-104 Experimental
General Chemistry I-II
CHE433 Special Topics: Surface
Science
Physical chemistry
education resources.
I am currently developing an upper level, interdisciplinary course on
nanoscience that will hopefully make its debut in a year or two.
Research Interests & Student Research
Opportunities
surface science / reaction dynamics
/ laser photochemistry /
laser-surface
interactions / nanotechnology
/ physical
chemistry / chemical
physics
My research
concentrates on the study of dynamical
processes at the surfaces of metals and semiconductors with a special
emphasis on structure formation and laser-surface interactions. Along
these lines my co-workers and I are studying photochemical and thermal
reactive
processes on surfaces. Of special interest are etching and growth
reactions to form nanoscale and larger structures.
A great deal of my work has involved pointed lasers at or
near surfaces and observing what happens. We use lasers to investigate
what is occurring at the surface; to probe the properties of interfaces
and porous materials; and to initiate chemical reactions and physical
changes in interfaces and porous materials.
The red image at the right is a photo I took of an ultrafast dye laser
that I used as NIST. The green
image at the left is a photo of a femtosecond Ti:sapphire of the type I
used in Birmingham and at UVa.
Dynamics of Adsorption and Desorption
I have long studied the simplest of surface chemical reactions, the
adsorption and thermal desorption of small molecules from surfaces,
particularly hydrogen
on silicon. Also I have recently reviewed stimulated
desorption of hydrogen from silicon. While this work has laid the
foundation
for much of my research, currently these are not the types of studies
that I'm performing in my lab in West Chester. Rather they are part of
what of do when I work with, for instance, Eckart
Hasselbrink in Essen, Germany.
Read more about the my studies of surface dynamics here.
Photochemical & Chemical Modification of Si and Porous Si
Si is an elemental semiconductor, the most widely used in
integrated circuit applications. Irradiation with laser light
fundamentally
alters the surface chemistry of silicon. For instance, whereas clean
crystalline Si is virtually inert to aqueous hydrofluoric acid,
irradiation of a Si
crystal immersed in HF(aq) with a cw visible laser can lead to
the formation of
porous Si . Once formed, the reactivity of
porous Si can also be altered by irradiation. We are studying these
processes in order to determine what factors affect the photochemical
reactivity of
Si surface and to develop a mechanistic understanding of the
photochemical
reactions involved.
We have also extended this work to investigate the formation of porous
silicon by purely chemical methods, so-called stain etching.
In stain
etching an oxidant is mixed with fluoride to form an aqueous solution
that spontaneously produces porous silicon once a silicon crystal has
been dipped in it. We have already shown
that the fluoride can be provided not only by HF but also by NH4HF2.
We are now investigating the role of the oxidant and how it can be used
to control both the photoluminescence spectrum and the morphology of
the por-Si film. The ferric ion, Fe(III), is one of the best oxidants
as it leads to uniform films that can be as much as 10 µm thick.
As described below, we make macroporous
silicon (porous silicon with very large pores) by etching
pillar-covered Si substrates in alkaline solutions.
For more on porous silicon click here.
Pillar Formation & Sharpening
Laser irradiation of
Si crystals under the appropriate conditions can lead to the
spontaneous formation
of conical structures. When made with a
femtosecond laser, these pillars can be ten or so micrometers long. The
tips, however, are on the order of a few hundred nanometers or less.
Using a nanosecond laser, the pillars are much larger, up to 100
µm or more and a few micrometers at their tip. We have also shown
that we can make such pillars in germanium
as well as titanium.
We have used alkaline solutions (concentrated KOH or
tetramethylammonium hydroxide, TMAH) to etch silicon pillars. Short
etching times produce sharpended pillars. When the pillars are
overetched, they disappear leaving behind macropores that are several
micrometers wide.
More on pillars and macropores can be found here.
Anodic Porous Alumina
This project just started. It involves electrochemically etching
aluminum to created ordered arrays of pores while simultaneously
oxidizing the aluminum to alumina (Al2O3). Read
more about it here.
Solidification Driven
Extrusion (Nanospikes)
While making silicon and germanium pillars, we noticed that nanoscales
spikes form
atop the pillars. We subsequently showed
that the same physics that is behind this phenomenon is also active in
your freezer and can result in the formation of centimeter long ice
spikes. Read more about this here.
Ultrafast Surface Photochemistry in the VUV
This was a project I worked on while at the University of Birmingham
that involves the use of femtosecond pulsed lasers to create vacuum
ultraviolet phtons via high harmonic generation.
Read more about it here.
Selected Recent Publications:
Wet Etching of Pillar Covered Silicon Surface: Formation of
Crystallographically Defined Macropores, Kurt W. Kolasinski and
Margaret E. Dudley, J.
Electrochem. Soc. 155, H164-H171 (2008).
Pillars formed by laser ablation and modified by wet etching, K.W.
Kolasinski, M.E. Dudley, B.K. Nayak, and M.C. Gupta, Proc. SPIE, 6586,
65860H (2007).
Catalytic growth of nanowires: Vapor-liquid-solid,
vapor-solid-solid, solution-liquid-solid and solid-liquid-solid growth,
Kurt W. Kolasinski, Curr. Op.
Solid State & Mater. Sci. 10, 182-191(2006).
Spontaneous formation of nano-spiked microstructures in germanium
by femtosecond laser irradiation, Barada K. Nayak, Mool C. Gupta and
Kurt W. Kolasinski, Nanotechnology
18, 195302 (2007).
Laser assisted and wet chemical etching of silicon nanostructures,
Kurt W. Kolasinski, David Mills and Mona Nahidi, J. Vac. Sci. Technol.
A 24, 1474-1479 (2006).
Silicon nanostructures from electroless electrochemical etching,
Kurt W. Kolasinski, Curr. Op.
Solid State & Mater. Sci. 9, 73-83 (2005).
Surface photochemistry in the VUV and XUV: High harmonic
generation, H2O and O2, Kurt W. Kolasinski, J.
Phys Cond. Matter 18, S1655-S1675 (2006).
Solidification driven extrusion of spikes during laser melting of
silicon pillars, David Mills and Kurt W. Kolasinski, Nanotechnology
17,
2741-2744 (2006).
Using effusive molecular beams and microcanonical unimolecular rate
theory to characterize CH4 adsorption on Pt(111), Kristy M.
DeWitt,
Leticia Valadez, Heather Abbott, Kurt W. Kolasinski and Ian Harrison,
J. Phys. Chem. B 110,
6705-6713 (2006).
Effusive molecular beam study of C2H6
dissociation on Pt(111),
Kristy M. DeWitt, Leticia Valadez, Heather Abbott, Kurt W. Kolasinski
and Ian Harrison, J.
Phys. Chem. B 110, 6714-6720 (2006).
The effects of stain etchant composition on the photoluminescence and
morphology of porous silicon, Mona Nahidi and Kurt W. Kolasinski, J. Electrochem. Soc.,
153, C19–C26 (2006).
The composition of fluoride solutions, Kurt W. Kolasinski, J. Electrochem. Soc.,
152, J99–J104 (2005).
Erratum: J. Electrochem. Soc.,
153, L28-L29 (2006).
Non-Adiabatic and Ultrafast Dynamics of Hydrogen Adsorbed on Silicon,
K.W. Kolasinski, Curr. Op.
Solid State & Mater. Sci, 8, 332-333 (2004).
The mechanism of Si etching in fluoride solutions, K.W. Kolasinski,
Phys.
Chem. Chem. Phys., 5, 1270 (2003) .
For a full list of publications click
here.
Textbook on Surface Science:
Kurt W. Kolasinski,
Surface Science: Foundations of Catalysis and Nanoscience (
John Wiley & Sons , Chichester, 2008). Second Edition now available!
Accompanying website
for the book, including the figures in pdf format
For further information on related topics,
try these sites:
Educational
Sites in Surface
Science, Nanotechnology and Catalysis
Web
Resources in Surface
Science, Nanotechnology and Catalysis
Journals
covering Surface
Science, Nanotechnology and Catalysis
Labs
working in Surface
Science, Nanotechnology and Catalysis
Chemistry,
Physics and Catalysis Societies
The Pittsburgh Penguins
Dynamics of
Gas-Surface Interactions
Association for the
Advancement of Sustainability in Higher Education
