A scientific advance in renewable energy which promises a revolution in the ease and cost of using solar cells, has been announced. A new study shows that even when using very simple and inexpensive manufacturing methods — where flexible layers of material are deposited over large areas like cling-film — efficient solar cell structures can be produced.

The research, published in the journal Advanced Energy Materials, makes way for new solar cell production techniques and the promise of advancements in renewable solar energy. Scientists from the Universities of Sheffield and Cambridge used the ISIS Neutron Source and Diamond Light Source at STFC Rutherford Appleton Laboratory in Oxfordshire to conduct the research.

Plastic (polymer) solar cells are much cheaper to create than traditional silicon solar cells and have the potential to be manufactured in large quantities. The research demonstrated that when complex mixtures of molecules in solution are spread onto a surface, like varnishing a table-top, the different molecules separate to the top and bottom of the layer in a way that maximises the efficiency of the resulting solar cell.

A polymer solar cell ready for testing. (Credit: Andrew Parnell)

Dr Andrew Parnell of the University of Sheffield said, “Our results give important insights into how ultra-cheap solar energy panels for domestic and industrial use can be manufactured on a large scale. Rather than using complex and expensive fabrication methods to create a specific semiconductor nanostructure, high volume printing could be used to produce nano-scale (60 nano-meters) films of solar cells that are over a thousand times thinner than the width of a human hair. These films could then be used to make cost-effective, light and easily transportable plastic solar cell devices such as solar panels.”

Dr. Robert Dalgliesh, one of the ISIS scientists involved in the research, said, “This work clearly illustrates the importance of the combined use of neutron and X-ray scattering sources such as ISIS and Diamond in solving modern challenges for society. Using neutron beams at ISIS and Diamond’s bright X-rays, we were able to probe the internal structure and properties of the solar cell materials non-destructively. By studying the layers in the materials which convert sunlight into electricity, we are learning how different processing steps change the overall efficiency and affect the overall polymer solar cell performance. ”

“Over the next fifty years society is going to need to supply the growing energy demands of the world’s population without using fossil fuels, and the only renewable energy source that can do this is the Sun,” said Professor Richard Jones of the University of Sheffield. ” In a couple of hours enough energy from sunlight falls on the Earth to satisfy the energy needs of the Earth for a whole year, but we need to be able to harness this on a much bigger scale than we can do now. Cheap and efficient polymer solar cells that can cover huge areas could help move us into a new age of renewable energy.”