Investing in graphene could be the brightest choice for investors if the latest research from Michigan University is to be believed. A solar energy future, with graphene at its very heart, has just come another step closer with the publication of research which shows a substantial boost to the efficiency of the next generation of solar panels.
Graphene’s electrical conductivity, could make it a key ingredient in the next generation of photovoltaic cells, says Yun Hang Hu, a professor of materials science and engineering.
Dye-sensitized solar cells don’t rely on rare or expensive materials, so they could be more cost-effective than cells based on silicon and thin-film technologies. But they are not as good at converting light into electricity.
In dye-sensitized solar cells, photons knock electrons from the dye into a thin layer of titanium dioxide, which relays them to the anode. Hu’s group found that adding graphene to the titanium dioxide increased its conductivity, bringing 52.4 percent more current into the circuit.
The excellent electrical conductivity of graphene sheets allows them to act as bridges, accelerating electron transfer from the titanium dioxide to the photoelectrode,” Hu said.
The team also developed a comparably foolproof method for creating sheets of titanium dioxide embedded with graphene. It first made graphite oxide powder, then mixed it with titanium dioxide to form a paste, spread it on a substrate (such as glass) and then baked it a high temperatures.
“It’s low-cost and very easy to prepare,” said Hu. But not just any recipe will do. “If you use too much graphene, it will absorb the light in the solar cell and reduce its efficiency,” he said.
Their work was presented at the US-Egypt Joint Workshop on Solar Energy Systems, held March 12-14 in Cairo. It was funded by the American Chemical Society Petroleum Research Fund and the National Science Foundation. Their paper “Promoting Effect of Graphene on Dye-Sensitized Solar Cells,” authored by Hui Wang, Samantha Leonard and Hu, has been submitted to Industry and Engineering Chemistry Research. Wang is a PhD candidate and Leonard is an undergraduate, both in materials science and engineering.
Michigan Technological University (www.mtu.edu) is a leading public research university developing new technologies and preparing students to create the future for a prosperous and sustainable world. Michigan Tech offers more than 130 undergraduate and graduate degree programs in engineering; forest resources; computing; technology; business; economics; natural, physical and environmental sciences; arts; humanities; and social science.
Original article http://www.mtu.edu/news/stories/2012/april/story67100.html