DuPont(TM) Kapton® Colorless Polyimide Film Enables World Record for Flexible CdTe Photovoltaic Efficiency

WILMINGTON, Del. (ots) -

New Superstrate Material Poised to Enable Flexible, Lightweight
and Efficient Thin Film Solar Modules

DuPont(TM) Kapton® colorless polyimide film, a revolutionary new
material currently in development for use as a flexible superstrate
for cadmium telluride (CdTe) thin film photovoltaic (PV) modules, has
enabled a new world record for solar cell conversion efficiency.
Empa, a leading research institute for material sciences and
technology development, based in Dübendorf, Switzerland, has
demonstrated a conversion efficiency of 13.8 percent using the new
DuPont(TM) Kapton® colorless film, leapfrogging their previous world
record of 12.6 percent and nearing that of glass.

Because Kapton® film is over 100 times thinner and 200 times
lighter than the weight of glass typically used for PV, there are
inherent advantages in transitioning to flexible, film-based vs.
rigid glass CdTe systems. High speed and low cost roll-to-roll
deposition technologies can be applied for high throughput
manufacturing of flexible solar cells on polymer film as substrates.
This new Kapton® film potentially enables significantly thinner and
lighter-weight flexible modules that are easier to handle and less
expensive to install, making them ideal for applications including
Building Integrated Photovoltaics (BIPV).

"Rather than transporting heavy, fragile glass modules on large
trucks and lifting them by crane onto rooftop PV installations, one
could imagine lightweight, flexible film-based modules that could
simply be rolled up for transport, and easily carried up stairs,"
said Robert G. Schmidt, new business development manager,
Photovoltaics - DuPont Circuit & Packaging Materials. "With
record-setting efficiency already established through EMPA, we're
confident this flexible, lightweight and durable material has the
potential to revolutionize the industry by enabling flexible design
and lowering balance of system costs."

Empa's Laboratory for Thin Films and Photovoltaics (
www.empa.ch/tfpv ) is involved in the research and development of
high-efficiency thin film solar cells with emphasis on novel concepts
for enhancing the performance of solar cells, simplifying the
fabrication processes, and advancing device structures for next
generation of more efficient and low-cost devices. They have been
doing groundbreaking work in developing and optimizing a low
deposition temperature (< 450 degrees Celsius) process for
high-efficiency CdTe solar cells on glass (15.6% efficiency) and
polymer film (12.6% efficiency). Although they established the
previous world record in the area of flexible CdTe, they have
continued to explore materials that would enable further advances.

"Finding a film that could both be transparent and withstand
high-processing temperatures was a challenge initially, but the new
Kapton® colorless polyimide film had both the tolerance for high
temperatures needed, and higher light transmittance due to its
transparency that allowed it to exceed our previous world record in
conversion efficiency of flexible CdTe solar cell," said Prof. Dr.
Ayodhya N. Tiwari, head of the laboratory - Empa. "As we continue to
raise the standards for PV efficiency, materials make a distinct
difference in the progress we make toward achieving grid parity. Of
course, further development is needed for addressing cost and
stability issues."

Empa plans to present a technical paper on the full findings of
its study at the 26th European Photovoltaic Solar Energy Conference
and Exhibition in Hamburg, Germany, being held Sept. 5 - 9, 2011.

DuPont(TM) Kapton® polyimide film has made innovative design
solutions possible in a range of industries over the last 45 years
including aerospace, automotive and industrial applications. With a
unique combination of electrical, thermal, chemical and mechanical
properties that withstand extreme temperature and other demanding
environments, Kapton® films have set the standards in high
performance, long-term reliability and durability, and are ideally
suited for applications in the PV industry. Three new Kapton® PV9100
series films were introduced for the thin film PV market in 2010,
including offerings for Amorphous Silicon (a-Si) modules and Copper
Indium Gallium Selenide (CIGS) photovoltaic applications.

DuPont is currently accepting requests for evaluation samples of
its new Kapton® colorless polyimide film for flexible CdTe
superstrate constructions and intends commercialization in 2012.
Additional Kapton® technologies are in development to further
increase the efficiency and lifetime of photovoltaic modules, reduce
overall system costs and help the industry reach grid parity faster.

DuPont(TM) Kapton® polyimide films are part of a broad and growing
portfolio of products represented by DuPont Photovoltaic Solutions,
which connects science and technology from across the company on a
global scale to help support the dramatic growth in the photovoltaic
industry. To learn more, please visit http://photovoltaics.dupont.com
.

DuPont ( www.dupont.com ) is a science-based products and services
company. Founded in 1802, DuPont puts science to work by creating
sustainable solutions essential to a better, safer, healthier life
for people everywhere. Operating in more than 90 countries, DuPont
offers a wide range of innovative products and services for markets
including agriculture and food; building and construction;
communications; and transportation.

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Suggested caption: New DuPont(TM) Kapton® colorless polyimide film
currently in development enables lightweight, flexible CdTe solar
modules that recently delivered a new world-record for conversion
efficiency. Photo courtesy of Empa.

The DuPont Oval Logo, DuPont(TM), The miracles of science(TM) and
Kapton® are registered trademarks or trademarks of DuPont or its
affiliates.

Presscontact:
Fiona Paul Pinter
Marketing Communications Manager
Photovoltaic Solutions, EMEA

Du Pont de Nemours International Sàrl
DuPont Photovoltaic Solutions
2, chemin du Pavillon - P.O. Box 50
CH-1218 Le Grand-Saconnex/Geneva

T: +41 (0)22 7175352
F: +41 (0)22 7176169
E: fiona.paul-pinter@che.dupont.com
www.photovoltaics.dupont.com