Extremely Efficient Small Molecule for Organic Solar Cells

BACKGROUND: Solar cells based on organic semiconductors are evolving into a promising cost-effective alternative to silicon-based solar cells due to low-cost and easy fabrication by solution processing, their light weight, and compatibility with flexible substrates. Devices based on these materials are predicted to have a theoretical efficiency approaching 10%. To date, solution processed small molecule based solar cell devices have power conversion efficiencies ranging from 0.3% to 1.3%. Higher efficiencies are sought via research efforts focused on the design and synthesis of new donor and acceptor materials with high charge carrier mobility and strong absorption in the visible and near-infrared regions of the solar spectrum.

DESCRIPTION: Researchers at the University of California have synthesized a low band gap, solution processable molecule functionalized with a highly absorbing chromophoric core. This molecule exhibits strong absorption in the visible and near-infrared regions of the solar spectrum. Thus, this compound is extremely well suited for solution-processed, small molecule-based bulk heterojunction (BHJ) solar cells. These solar cells exhibit the highest reported power conversion efficiency to date for the class of small molecule-based BHJ solar cells. These materials can also be used as sensitizers for near-infrared absorption in polymer BHJ solar cells.


* Excellent power conversion efficiency
* Quasireversible oxidation and reduction processes
* Strong film absorption extending to 800nm, versus 700nm for other solution processed small molecules
* Ordered aggregation in the solid state
* No large phase segregation observed in blends at various donor/acceptor ratios
* Comparable hole mobility to small molecules and conjugated polymer materials used for BHJ solar cells
* Large absorption cross section


* Organic solar cells
* Thin film transistors


* "A Low Band Gap, Solution Processable Oligothiophene with a Diketopyrrolopyrrole Core for Use in Organic Solar Cells" Arnold B. Tamayo, Bright Walker, and Thuc-Quyen Nguyen, J. Phys. Chem. C, Vol. 112, No. 30, 2008

This technology is available for licensing. Patent Pending.

REFERENCE: 2009-290

Type of Offer: Licensing

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