Organic Photovoltaics 2009 Examines Gains in OPV Technology

By David Savastano

Stuart Spitzer, Russell Gaudiana, Terri Jordan and Srini Balasubramanian of Konarka Technologies.
The field of organic photovoltaics (OPV) is one of the most promising areas of business, as interest in clean energy technology grows. Unlike traditional silicon-based PV, OPVs are low cost, lightweight and flexible, which offers tremendous possibilities for applications. There do remain challenges, notably lifetimes of these cells and efficiency levels, which still are in the 3 percent to 5 percent range.

These challenges are being met. In order to look at some of the most recent advancements in the field of OPVs, Intertech Pira hosted Organic Photovoltaics 2009 at the Doubletree Hotel Philadelphia, a conference that featured speakers from leading OPV manufacturers as Konarka Technologies, Luna Innovations, Plextronics and Solarmer Energy, as well as suppliers and academics.

After welcoming remarks from opening session co-chair Russell Gaudiana, VP research for Konarka Technologies, Inc., Sean Shaheen, associate professor, University of Denver, discussed “Recent Progress in Understanding the Device Physics of Organic Photovoltaics.” He noted that the world “is undergoing a technological and societal phase transition,” which OPV can be a part of due to its potential to provide new clean energy sources.

Mario LeClerc, professor, Universite Laval in Canada, followed with “Solar Cells Based on Conjugated Polycarbazoles,” a look at the synthesis of new conjugated polymers. “New Theory Developments and Experiments on Optimal Donor-Acceptor Frontier Orbital Energies” was the topic of Kees Hummelen, professor, University of Groningen in The Netherlands.

Christine McGuiness and Darin Laird of Plextronics.
Martin Drees, research scientist at Luna Innovations Inc., presented “Novel Acceptor Materials for Organic Solar Cells,” an overview of acceptor materials and requirements for new acceptors, including trimetallic nitride endohedral fullerene acceptors. Michael Diener, TDA Research, followed with “New Fullerene Derivatives for OPV,” another look at fullerenes. “Quantum chemical calculations of fullerenes predict significant further improvements are possible – but can they be synthesized and are the products sufficiently stable?” Diener concluded.

The morning session closed with “Solution Processable Nanocomposite Materials for Application in Organic Electronics,” presented by Alan Sellinger, consulting associate professor at Stanford University and executive director of the Center for Advanced Molecular Photovoltaics (CAMP).

The afternoon session began with “Microstructure of Polymer: Fullerene Blend Films for Organic Photovoltaics,” presented by Jenny Nelson, professor of physics at Imperial College London. “Transparent Conducting Carbon Nanotube Electrodes for OPV” was the topic of Jeremy Bergeson, postdoctoral researcher at the National Renewable Energy Laboratory (NREL). Steve Ransome, director of Steve Ransome Consulting, analyzed “Outdoor Testing of New PV Technologies.”

Dina Lozofsky and Yue Wu of Solarmer Energy.
“Lifetime of Organic Photovoltaic Modules Under Accelerated Aging Conditions,” a look at lifetime of modules in damp heat and continuous light exposure conditions, was the topic of Srini Balasubramanian, R&D lab manager at Konarka Technologies. Max Shtein, professor at University of Michigan, closed the first-day session with “Non-Planar Organic Solar Cells as Building Blocks for Energy Converting Textiles.”

New OPV Technologies

The April 29 session began with opening remarks by Dana Olson, research scientist of NREL, followed by Stuart Spitzer, VP of engineering for Konarka Technologies, who discussed “New Market Opportunities Enabled by a Highly Scalable Organic Photovoltaic Manufacturing Process,” looking at the potential of the roll-to-roll manufacturing process and the strong progress being made by Konarka.

“Commercialization of OPV: Development of Inks for Low Cost Solar Applications,” a technical review of current ink products as well as progress in OPV lifetimes, was the topic of Darin Laird, director of technology, power team for Plextronics.

“Plastic Solar Cell Technology: Expanding the Horizon,” by Yue Wu, director of research for Solarmer Energy, discussed the gains being made by Solarmer. Wu noted that the company is aiming for 8 percent efficiency and three-plus years of lifetime.

Rong Bao, research fellow, Fusion UV Systems, followed with “UV Curing Characteristics and its Future Applications in the OPV Industry,” a look at UV. “Production Technologies for Flexible Solar Cells and Parameters for Printing and Coating Processes,” presented by Thomas Kolbusch, managing director, Solarcoating Machinery GMBH, concluded the conference.

The conference chairs were pleased with the program. “I thought it went pretty well,” said Gaudiana. “We hit a variety of subjects, including several papers or receptors, which has been an area lacking in attention.”

“There were a lot of good conversations on technology, where things are and where they are going,” added Olson. “There is a lot of good progress in terms of efficiencies and lifetimes.”