It is hoped the findings, which saw a novel set of self-assembling molecules that can turn sunlight into electricity being repeatedly broken down and reassembled quickly, will help to extend the lifetimes of the cells.
Michael Strano, Charles and Hilda Roddey Associate Professor of Chemical Engineering at MIT, who developed the research along with his team of graduate students and researchers, said that that in devising novel systems for generating electricity from light, researchers dont often study how the systems change over time.
He said that for conventional silicon-based photovoltaic cells, there is little degradation, but with many new systems being developed – either for lower cost, higher efficiency, flexibility or other improved characteristics – the degradation can be very significant. Often people see, over 60 hours, the efficiency falling to 10 percent of what you initially saw, he explained.?
The individual reactions of these new molecular structures in converting sunlight are about 40 percent efficient, he continued, or about double the efficiency of todays best solar cells. Theoretically, the efficiency of the structures could be close to 100 percent, he added. But in the initial work, the concentration of the structures in the solution was reportedly low, so the overall efficiency of the device – the amount of electricity produced for a given surface area – was very low. The researchers have said they are working now to find ways to greatly increase the concentration.