SBU Grad Students Help Pioneer New Approach for Improving Solar Cells

Two Stony Brook University graduate students are part of a research team that is exploring the promise of a new approach for improving solar cells, photocatalysts, light sensors, and other optoelectronic devices.

The research team at a probe station where they used simulated sunlight to characterize electronic devices they’d made using a hybrid nanomaterial (back to front: Chang-Yong Nam and Mircea Cotlet of Brookhaven Lab’s Center for Functional Nanomaterials with Stony Brook University graduate students Prahlad Routh and Jia-Shiang Chen).

Optoelectronic devices detect and control light, harnessing the power of the sun to create and use energy in sustainable ways. New technologies in this field promise cheaper, more environmentally sustainable ways of generating power.

Creating light-harvesting devices requires a material that both absorbs light efficiently and converts the energy to highly mobile electrical current. Finding the ideal mix of properties in a single material is a challenge, so scientists have been experimenting with ways to combine different materials to create “hybrids” with enhanced features.

In two just-published papers, scientists from the U.S. Department of Energy’s Brookhaven National Laboratory, Stony Brook University, and the University of Nebraska describe one such approach that pairs “quantum dots” — nano-scale semiconductors that regulate the flow of electricity — with tin disulfide semiconductors. The research paves the way for using these materials in optoelectronic applications such as energy-harvesting photovoltaics, light sensors, and light emitting diodes (LEDs).

Stony Brook is one of seven universities with a role in running a national laboratory. The relationship provides many opportunities for hands-on collaborative research efforts involving Stony Brook students with world-class BNL scientists.

SBU graduate students Prahlad Routh and Jia-Shiang Chen worked with the research team at a probe station where they used simulated sunlight to characterize electronic devices they’d made using a hybrid nanomaterial.

“We have come up with an interesting approach to discriminate energy transfer from charge transfer, two common types of interactions promoted by light in such hybrids,” said Routh, who is working with Cotlet and is listed as co-first author of one of the papers.

“We do this using single nanocrystal spectroscopy to look at how individual quantum dots blink when interacting with sheet-like tin disulfide. This straightforward method can assess whether components in such semiconducting hybrids interact either by energy or by charge transfer.”

Brookhaven National Laboratory is managed on behalf of the U.S. Department of Energy by Brookhaven Science Associates, a partnership between the Research Foundation for the State University of New York on behalf of Stony Brook University and Battelle.