Washington, August 5 A team of scientists has found a way to make nanostructured plastic solar cells, which are roughly 10,000 times smaller than a human hair.
A research team headed by David Ginger, a University of Washington associate professor of chemistry, has developed the new technology.
Researchers the world over are striving to develop organic solar cells that can be produced easily and inexpensively as thin films that could be widely used to generate electricity.
But a major obstacle is coaxing these carbon-based materials to reliably form the proper structure at the nanoscale (tinier than 2-millionths of an inch) to be highly efficient in converting light to electricity.
The goal is to develop cells made from low-cost plastics that will transform at least 10 percent of the sunlight that they absorb into usable electricity and can be easily manufactured.
Now, Ginger's research team has found a way to make images of tiny bubbles and channels, roughly 10,000 times smaller than a human hair, inside plastic solar cells.
These bubbles and channels form within the polymers as they are being created in a baking process, called annealing, that is used to improve the materials' performance.
The researchers are able to measure directly how much current each tiny bubble and channel carries, thus developing an understanding of exactly how a solar cell converts light into electricity. inger believes that will lead to a better understanding of which materials created under which conditions are most likely to meet the 10 percent efficiency goal.
"As researchers approach that threshold, nanostructured plastic solar cells could be put into use on a broad scale," he said.
As a start, they could be incorporated into purses or backpacks to charge cellular phones or mp3 players, but eventually they could make in important contribution to the electrical power supply.
For the current research, the scientists worked with a blend of polythiophene and fullerene, model materials considered basic to organic solar cell research because their response to forces such as heating can be readily extrapolated to other materials.
The materials were baked together at different temperatures and for different lengths of time.
Ginger noted that the polymer tested is not likely to reach the 10 percent efficiency threshold.
"But the results will be a useful guide to show which new combinations of materials and at what baking time and temperature could form bubbles and channels in a way that the resulting polymer might meet the standard," he said. (ANI)
