Three Dimensional Oligomeric Electron Acceptor Layers for Organic Photovoltaic Devices

Principal Investigator: Samson Jenekhe

Silicon solar cells are bulky, rigid, and must be oriented so that the incident light is directly perpendicular to the cell surface in order to harvest light efficiently. A number of alternatives, including thin film inorganic, hybrid perovskite, and organic photovoltaics, hold promise for low production cost, light-weight and bendable cells, and films that can absorb light at a range of angles. Perovskite and organic cells require an electron acceptor layer that can separate the electric charges generated by photons and transport those electrons to the electrodes. Fullerene (C60 and C70) derived compounds are the state of the art for these layers, but suffer from high cost, poor yield, and poor solubility and interlayer miscibility.

Researchers in the Jenekhe lab have developed oligomeric electron acceptors enabling better performance than expensive fullerenes. These oligomers feature a structural twist that imparts a three dimensional molecular structure, enhancing the separation of photogenerated charges. Large pi-conjugated chromophore groups offer enhanced optical absorbance and quantum efficiency, as well as generating higher photovoltages. Bulk heterojunction OPV devices produced using these materials have reached efficiencies of 8.5%, better than the fullerene state of the art.

Applications

• Organic photovoltaics (OPV) 

• Perovskite photovoltaics 

• Organic field effect transistors (OFETS) 


Advantages

• Tunable structures for optimization of solubility, miscibility, optical properties, and 3D structure 

• Device efficiencies which meet or exceed state-of-the-art fullerene layers 

• Lower cost of materials and processing over incumbents


For more info, contact: Forest Bohrer