European projects to aid organic photovoltaic development

Sara Ver-Bruggen - 14 Feb 2012

The current trend in R&D for the organic photovoltaic (OPV) industry in Europe is laying foundations for the next generation of organic solar cells.

OPV technologies and processes being developed by Heliatek, Konarka, and other companies such as Solarmer and Eight19 eschew conventional PV production to print or coat cells, feeding flexible substrates through high-throughput tools. Module efficiencies are low, rating at less than 5%, while lifetimes are also short.

Different methods

To compete with other PV technologies in the long-term, especially second-generation thin-film, OPVs need to maximise efficiencies and lifetimes, while leveraging cost-effective processing techniques.

Konarka and Heliatek represent two distinct approaches to producing so-called third- generation solar cells, or OPVs. Konarka's technology centres on printing solution-processable materials as inks on roll-to-roll equipment, inherited from Kodak. Heliatek is developing a roll-to- roll vacuum process - a proven, scalable approach for producing other organic electronic devices such as OLED displays and lamps.

Konarka is part of the Sunflower project, to develop cells of 12% efficiency and produce modules of between 8-10%, 20-year lifetimes at less than €0.70 per watt peak, ahead of achieving economies of scale. Different printing techniques will be deployed.

Meanwhile the X10D project, coordinated by Belgian R&D centre Imec, spans vacuum processing and printable organic solar cell technologies. End user partners are Heliatek and Solarpress.

The challenge is to make tandem and multi- junction cells, which requires new absorber materials in a combination that harvests light across the spectrum - including the red portion of the spectrum - while ensuring electrical performance across the different absorber materials is similar.

Heliatek and Solar Press can use the project to inform the development of their facilities and lines, to best optimise device architecture and identify which process steps require further adaptation or modification. There are other supply chain opportunities for commercial partners too. Cost analysis is a critical aspect of the project, with the goal of making breakthroughs suitable for roll-to-roll production.

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