Organic photovoltaics developer Solarmer Energy has achieved the highest conversion efficiency recorded so far for a plastic OPV champion cell—7.9%. The aperture-area test results, recently certified by the U.S. Department of Energy’s National Renewable Energy Laboratory, represent an improvement over independent exams conducted a few months ago at Newport Corp.’s Technology and Application Center’s PV Lab, where cell efficiencies of 7.6% and module efficiencies of 3.9% were recorded.
Yue Wu, Solarmer’s director of production technology, told PV-Tech that the El Monte, CA-based company sent two samples comprised of four 0.1 cm2 cells to the national lab. Aperture areas of 0.047 cm2 were then created on the cells before the measurements were taken. In addition to the efficiency numbers, a fill factor of 70.87% was seen.
The latest efficiency results compare favorably with the goals set by Solarmer a year ago, according to Wu. “We had a plan and followed it exactly; actually, the results were a little higher than [we] expected.”
“It’s the best organic device we’ve seen to date, period,” said industry veteran Keith Emery, who manages NREL’s PV cell and module performance and characterization team. “That’s a milestone for the technology in and of itself, so we updated the chart where we keep efficiency versus time at the cell level for various technologies. This is a new point on that plot.”
Emery told PV-Tech that “it’s really nice to see Solarmer making such a steady improvement. Their rate of improvement is not slowing down, and there’s no reason to believe they won’t be making better cells in another few months.”
The company’s roadmap calls for the achievement of 10% conversion efficiencies on its OPV cells by the end of 2010.
Solarmer’s Wu, who will be presenting the new data and other company updates at the Printed Electronics USA/Photovoltaics 2009 event in San Jose this week, said that the company is “building its pilot line right now.”
The roll-to-roll “proof of manufacturability” line will be operational by “the middle of next year” or sooner, and he believes “we will have some commercial grade panels ready” soon afterwards.
Solarmer’s roadmap calls for the first full-scale manufacturing line to become operational in early 2011, with the initial commercial product launch to occur during that same time-frame.
In addition to driving toward low-cost, high-throughput production, work is ongoing at Solarmer in materials development, according to Wu, with efforts on the "chemical design [of the donor polymers] to optimize the energy bandgaps...and to balance the current and voltage that the materials can generate."
The company is also working to improve device lifetimes and performance, with focus on the identification of key degradation mechanisms, the development of advanced moisture encapsulation methods, the creation of standard OPV test methods, and the evaluation of the modules in indoor and outdoor testing scenarios.
The first major applications for the company’s flexible OPV technology will likely be mobile phones and other portable digital electronic devices, as well as “smart” solar tents, bags, and other fabric items, with building-integrated PV, in the form of power windows, to follow.