10 February 2012
Polyera Corporation, a materials supplier for the electronics and opto-electronics industries, has achieved a certified world-record 9.1% efficient polymer/fullerene organic solar cell in an inverted bulk heterojunction architecture using proprietary ActivInk PV2000 semiconductor material.
Who is this company behind the world record? Located outside Chicaco, Illinois (US), Polyera started as a spin-out of technology developed in Prof. Tobin J. Marks’ group at Northwestern University. Prof. Marks is the Charles E. and Emma H. Morrison Professor of Chemistry, Professor of Materials Science and Engineering and Vladimir N. Ipatieff Professor of Catalyic Chemistry. Dr. Antonio Facchetti, one of the post-doctorates in Prof. Marks’ group as well as Polyera co-founder and CTO, had lead most of the work on creating novel, high-performance, solution-processable n-type semiconductors. “We licensed the original IP from [Northwestern] and have since developed our own—over 140 patents—and most of the substantial research we do now takes place in-house,” says Brendan Florez, Assistant General Manager of Polyera. “ActivInk PV2000, for example, is a Polyera invention.”
The significance of this achievement lays in the combination of the material’s world-record efficiency in an inverted architecture and properties unique to organic solar cells—such as the ability to be light, flexible and optically semi-transparent. “High efficiency is of course extremely important, but that doesn't mean much if you can't actually get to commercial product with that material,” Florez explains. “This requires lots of factors: relatively low cost and complexity of synthesis, ability to use environmentally friendly solvents, ease of processing, stability, lifetime, color, etc. - the list can get quite long. The exciting thing about this material is that it has high efficiency while also having the other properties that make it a very strong candidate for real-world, mass-scale applications.”
Inverted cell architecture provides a number of benefits vital for commercial applications, such as making solar panels easier to manufacture. Polyera’s active layer materials, for instance, can also be deposited using a significantly broader range of film thicknesses and require low enough process temperatures to be compatible with a wide range of simple printing processes and common, inexpensive plastic substrates. For confidentiality reasons, though, Florez did not want to elaborate further on their ActivInk material used in the world-record experiment. “Materials composition is our ‘secret sauce’”, he says. Their press release reveals this much: Polyera focused on the chemistry of semiconductor materials and “found a new way to design and combine the active layer building blocks to maximize certain optical and electrical properties.”
Sponsorship for the record-breaking OPV study came from two sources, says Florez: “Investors in Polyera and, most recently, a two-million dollar grant from the National Institute of Standards and Technology (NIST) to help us focus on the development of novel synthesis pathways to help scale these materials in a cost-effective way to enable true commercialization.”
Indeed, the Polyera team feels confident this latest world-record OPV cell efficiency brings them a significant step closer to enabling true commercialization. “The area of organic photovoltaics is an emerging field, so we work very closely with customers to understand their needs and meet them,” Florez says. “The active layer materials we're creating are one of the key enabling elements of making OPV a viable technology, and we plan on making that happen.”
Polyera is currently exploring potential Joint Venture partnerships to help capitalize on this technology.
Written by Sandra Henderson, Research Editor, Solar Novus Today