Research interests
The future of modern
life is
dependent on our ability to sustain our environment. With the
increasing
financial and strategic costs of conventional fuels, turning to
alternative
energy sources, such as solar energy, is the natural choice. Molecules
and organic
materials (“plastics”) offer an inexpensive
alternative to traditional semiconductors, with unparalleled
flexibility in
design of structure-properties relations. Basic research on the
fundamental opto-electronic properties of molecules, and their
dependence on their
structure, is needed to fully exploit their potential.
Our basic
interest is in characterization through a ‘bottom
up’ approach – if the
properties of a single building block are understood, can the
properties of the
whole system be deduced? Can a better system be designed by designing
the
single building block? This approach will be applied to studying
molecular
building blocks of solar cells and light-activated microelectronic
devices.
High resolution
microscopy and recently developed methods allow measuring the
electronic
properties of very small objects – down to the nano-scale
(1/million of the
thickness of a single human hair). Thus, it allows us to examine a
single
molecule, to study the molecular structure-properties relations with
respect to
solar and other alternative energy production pathways, without the
need to
average over many molecules. This way it is plausible to design and
build a
system of desired properties, such as a solar cell, from its
fundamental –
molecular- building blocks.
Using such
methods allow characterization of the effect of illumination on the
properties
of a single molecule and other organic photovoltaic building blocks,
which
could not be characterized before. Fundamental understanding of the
molecular
machinery of biological photosystems, such as those involved in
photosynthesis,
could provide the knowledge needed to design artificial, bio-inspired
materials
for solar photovoltaics. Such measurements will contribute to design of
better
solar cells, understanding of fundamental biological processes, and the
basic
mechanisms of interaction of molecular electronic properties with
external
illumination. As such, this innovative research combines biological
physics,
molecular
electronics, solar energy and condensed matter physics, and has
implication both for basic
science and the
applicative one.
Selected publications
1.
D. Azulay, O. Millo, I. Balberg, H-W.
Schock, I.
Visoly-Fisher, D. Cahen, Current routes in polycrystalline CuInSe2
and Cu(In,Ga)Se2 films, Sol. Ener. Mater. & Sol.
Cells,
91 (2007) 85–90.
2.
I. Visoly-Fisher, K. Daie, Y.
Terazono, C. Herrero, F. Fungo, L. Otero, E. Durantini, J. J. Silber,
L.
Sereno, D. Gust, T. A. Moore, A. L. Moore, S. M. Lindsay, Conductance
of a
biomolecular wire, PNAS, 103 (2006) 8686-90.
3.
I. Visoly-Fisher, S. R. Cohen,
K. Gartsman, A. Ruzin, D. Cahen, Understanding
the Beneficial Role of Grain Boundaries in Polycrystalline Solar Cells
from
Single Grain Boundary Scanning Probe Microscopy, Adv.
Funct. Mater., 16 (2006) 649-660.
4.
I. Visoly-Fisher, A. Sitt, M.
Wahab, and D. Cahen, Molecular Adsorption-Mediated Control over the
Electrical Characteristics of Polycrystalline CdTe/CdS Solar Cells, ChemPhysChem,
6 (2005) 277-85.
5.
I. Visoly-Fisher, S. R. Cohen,
A. Ruzin, D. Cahen, How polycrystalline devices can out-perform
single
crystal ones: thin film CdTe/CdS solar cells, Adv. Mater., 16
(2004) 879-83.
6.
I. Visoly-Fisher, S. R. Cohen, C.
S. Ferekides, D. Cahen, Electronically Active Layers and Interfaces
in
Polycrystalline Devices: Cross-Section Mapping of CdS/CdTe Solar Cells,
Appl.
Phys. Lett., 83 (2003) 4924-6.
7.
I. Visoly-Fisher, S. R. Cohen, D.
Cahen, Direct Evidence for Grain-Boundary Depletion in
Polycrystalline CdTe
from Nanoscale-Resolved Measurements, Appl. Phys. Lett., 82
(2003) 556-8.
8.
I. Visoly-Fisher, K. D. Dobson, J. Nair,
E. Bezalel, G. Hodes,
D. Cahen, Factors Affecting the Stability of CdTe/CdS Solar Cells,
Deduced
from Stress Tests at Elevated Temperature, Adv. Funct. Mater.,
13
(2003) 289-99.
9.
K. D. Dobson, I. Visoly-Fisher, G. Hodes
D.
Cahen, Stabilizing CdTe/CdS Solar Cells with Cu-Containing Contacts
to
p-CdTe, Adv. Mater., 13 (2001) 1495-9.
10.
K. D. Dobson,
I.
Visoly-Fisher, R. Jayakrishnan, K. Gartsman, G. Hodes, D. Cahen, When,
Why and Where are CdTe/CdS Solar Cells Stable?, in: R. Birkmire,
R.
Noufi, D. Lincot and H-W Schock (Eds), II-IV Compound Semiconductor
Photovoltaic Materials, MRS Symp. Proc. vol. 668. p.
H8.24.1-24.6 (2001).
11.
K. D. Dobson,
I.
Visoly-Fisher, G. Hodes, D. Cahen, Stability of CdTe/CdS Thin-Film
Solar
Cells (review paper), Sol. Energy Mater. Sol. Cells, 62
(2000)
295-325.
12.
M. S. Silverstein, I.
Visoly-Fisher, Plasma Polymerized Thiophene: Molecular Structure
and
Electrical Properties, Polymer, 43 (2002) 11-20.