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[bob ford <bobford79 AT yahoo.com>]

I can't tell from the article just how promising this is...............

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Cheaper Plastic Solar Cells In the Works

livescience.com – Sat Dec 13, 9:09 am ET


Sunlight, or solar radiation, is a remarkable phenomenon. It is the energy 
source in photosynthesis, makes us warm on summer days, and if future solar 
cells can be made more efficient and less costly, it may be our best source 
for reliable, clean and renewable energy.

As a postdoctoral researcher in the South Dakota State University (SDSU) 
Department of Electrical Engineering, I am working with my advisor Qiquan 
Qiao, an assistant professor in the department's Center for Advanced 
Photovoltaics, and Seth Darling, an assistant scientist at the Department of 
Energy's Argonne National Laboratory Center for Nanoscale Materials, to 
design, synthesize and eventually fabricate a more efficient and less costly 
solar cell.

We are trying to develop a cell that addresses the main challenge facing 
solar energy devices: absorb more of the sun's energy for electricity 
production.

Plastic cells

Unlike the vast majority of today's solar cells, which are expensive because 
they are made from silicon-based, or inorganic, semiconductors, the solar 
cell we are creating will be less costly as it will be made from organic, or 
carbon-based, semiconductors made from polymers. We will use two different 
types of polymers: one which is electron-deficient, an organoborane polymer, 
and one which is electron-rich, a thiophene polymer. 

Since my skills are focused on creating organoborane molecules, which are 
made from carbon, boron and hydrogen, I rely heavily on Qiao, who is an 
expert in the physics of solar cells, and Darling, who is an expert in 
self-assembly and chemical computation. As we each have expertise in 
specialized areas of science, putting our ideas together to make this project 
work is really a great interdisciplinary research collaboration! 

The organoborane and thiophene polymers are chain-like molecules made from 
carbon, boron, sulfur and hydrogen. These polymers have alternating double 
bonds and are flat, characteristics necessary for electrons to travel through 
the backbones of the polymers and produce electricity. 

When we connect the organoborane and thiophene polymers, each with opposing 
electronic properties, we will create a "molecular p-n junction," key to 
collecting and using electrons for electricity.

By synthesizing the p-n junction within the polymer molecules, we hope to 
overcome many of the limitations of current organic solar cells. 

Additionally, we will incorporate molecules known to absorb different 
wavelengths of light into the polymer chains. By doing this, we hope that 
these polymers will be able to absorb nearly the entire spectrum of visible 
light, which has wavelengths ranging from approximately 400 nanometers 
(violet light) to 750 nanometers (red light), thereby harnessing much more of 
our sun's energy.

Self-assembling arrays

One reason my collaborators and I chose to research these polymers is because 
they may be capable of self-assembling in just a few seconds to form very 
tiny, ordered arrays of materials. The arrays will allow the electrons to 
more easily find their path out of the ordered blocks to produce electricity. 

The proposed solar cell would consist of approximately 1015, or one 
quadrillion, polymer molecules enclosed in an area of just one square 
centimeter.

The immediate goal for our research project is to develop a greater 
understanding of this class of materials, knowledge that will be used down 
the line to develop and fabricate our proposed solar cell. 

Printing cells

To identify which polymer structures best fit our requirements, I have been 
using a commercial computational chemistry software program that will give me 
direction for the biggest challenge of this project, which will be making and 
characterizing these polymers. 

These solar cells may be inexpensive to produce because the organic polymers 
can be created using low-cost techniques like reel-to-reel processing, 
similar to the method behind newspaper printing, which results in a material 
that is lightweight and mechanically flexible. 

In September 2008, I was awarded an inaugural National Science Foundation 
American Competitiveness in Chemistry Fellowship, a two-year grant that is 
giving me an opportunity to both contribute to U.S. competitiveness and to 
involve students from traditionally underrepresented groups in this important 
area of science. I plan to develop a solar cell laboratory for the Chicago 
Science Alliance, which supports science teachers in the Chicago Public 
Schools, and to work with my advisor to develop hands-on activities 
describing solar cell materials for inclusion in a mobile science laboratory. 
The lab would travel across South Dakota to reach small rural schools as well 
as schools on Native American reservations. 

Video - Major Discovery: Solar Revolution? 
What Ever Happened to Solar Power? 
You and the Sun: 10 Burning Questions 

Editor's Note: This research was supported by the National Science Foundation 
(NSF), the federal agency charged with funding basic research and education 
across all fields of science and engineering. See the Behind the Scenes 
Archive. 

http://news.yahoo.com/s/livescience/20081213/sc_livescience/cheaperplasticsolarcellsintheworks