Credit: SDSU Research News

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Logue’s work is included in an EPSCoR grant of $6.75 million for collaborative work involving researchers at South Dakota State University, the South Dakota Schoolof Mines and Technology, and the University of South Dakota. Logue is one of several researchers focusingon research infrastructure in Photo Active Nanoscale Systems (PANS). The main purpose is developing photovoltaics, or devices that will directly convert light to electricity.

“I’m working on what are called ‘dye-sensitized solar cells.’ This type of solar cell is modeled after plants,” Logue explained.

A plant has a dye, chlorophyll, attached to something that can accept an electron from the dye after it absorbs light and becomes excited. The plant will change that electron into energy. “So what a dye-sensitized solar cell does is use a semi-conductor like a regular solar cell, but you attach a dye to it,” Logue said. “The dye is what absorbs the light and then it pushes an electron around a cell to power a calculator, for example.”

Logue and his colleagues are looking at existing dyes, but they’re also working to !nd new ones. “We are developing dyes that absorb infrared radiation and are looking to integrate those dyes in a dye-sensitized solar cell. Most current dyesensitized solar cells do not absorb the infrared part of the solar spectrum,” Logue said.

That is why Logue, a chemist, has spent time pondering how plants work. “That has been a big push in the past 10 to 15 years, to look at nature to see how nature does it and then try to mimic that. You’re never going to follow it exactly, of course, because nature is so complex in what it does. Even this dye-sensitized solar cell mimics only a small part of what happens in a plant. But it actually works pretty well.”

Logue’s collaborators in SDSU’s Department of Electrical Engineering and Computer Science include professor David Galipeau, associate professor Michael Ropp, research assistant professor Qiquan Qiao, research assistant professor Hongshan He, research assistant professor XingZhong Yan, andassistant professor Mahdi Baroughi. He also collaborates with assistant professor Youngjae You in the SDSU Department of Chemistry and Biochemistry.

Logue also collaborates with University of South Dakota colleagues, including professor Mary Berry, assistant professor Ranjit Koodali, professor Stanley May, and research assistant professor James Hoefelmeyer. Professor Jon Kellar at the South Dakota School of Mines and Technology is another collaborator in the research.

The ultimate goal of researchers is to bring the cost of solar cells in linewith fossil fuels, and therefore decrease dependence on fossil fuels. “If we can bring that cost down, then perhaps all the new houses made would have solar cells to power them and then they would be largely selfsustaining,” Logue said. “Solar cells are a decentralized source of energy, so you can put them on houses and run the electricity of the houses without having to get the electricity from the power grid.”

Homes probably still would rely somewhat on the power sources theyhave today because sunlight isn’t available round the clock, Logue said. But research at SDSU and elsewhere is aimed at using photovoltaic devices to tap an increasing share of energy from the sun.