Polymer-based method for creating photovoltaic devices

A promising new polymer-based method for creating photovoltaic devices, which convert sunlight into electricity, has been identified by chemists at the University of Massachusetts Amherst. Their new technique should lead to more efficient power production than achievable by the current generation of semiconductors.

The work by Sankaran Thayumanavan and colleagues at UMass Amherst, with others at the University of California-Riverside, mimics nature’s way of harnessing solar energy.

To achieve the breakthrough, Thayumanavan and coworkers took inspiration from plants and experimented with organic molecules to mimic the photosynthetic machinery of plants. Their work demonstrates how a photosynthesis-style photovoltaic device can be designed using large, highly branched, non-biological organic molecules called dendrimers, based on plant anatomy. Branches allow the dendrimer to absorb photons from a wide area and funnel this energy to the dendrimer’s core where it is connected to a polymer ‘wire’. At the core, charge is separated and the electrons travel down the polymer ‘wire’ to an electrode where electricity is produced.

As Thayumanavan explains, “Our method is inspired by an energy-harnessing process that plants use in nature, which evolved over millions of years to be efficient in terms of capturing a lot of energy and transporting it short distances without power loss. In the future, photovoltaic devices may no longer rely on slower, less efficient human-made semiconductors. Our work should lead to lighter, more efficient and sustainable photovoltaics.” Thayumanavan, known to colleagues as Thai, is director of the UMass Amherst’s Fueling the Future Center for Chemical Innovation.