12-01 :: January 2012
nanotimes News in Brief
into cylinders,” Ghosh said. “The results of this architectural redesign surprised us, as it significantly improves their efficiency.” The main problem preventing luminescent con- centrators from being used commercially is that they have high rates of self-absorption, Ghosh said, meaning they absorb a significant amount of the light they produce instead of transporting it to the solar cells.
Image: Diffusional behavior of a spherical probe through static nematogens (or needles) is probed via molecular dynamics simulations. © Gatech
Ashley K. Tucker and Rigoberto Hernandez: Diffusion of a Spherical Probe through Static Nematogens: Ef- fect of Increasing Geometric Anisotropy and Long-Ran- ge Structure, In: The Journal of Physical Chemistry B, Volume 116, Issue 4, February 2, 2012, Pages 1328- 1334, DOI:10.1021/jp207346j: http://dx.doi.org/10.1021/jp207346j
The research team showed the problem can be addressed by changing the shape of the concen- trator. They discovered a hollow cylindrical solar concentrator is a better design compared with a flat concentrator or a solid cylinder concentrator. The hollow cylinders absorb more sunlight while having lower self-absorption losses. The biggest advantage they offer over traditional solar cells is that they can work even in diffuse sunlight, like on cloudy days. And because of this, they do not need to directly face the sun at all times, eliminating the need for tracking mechanisms. Ghosh said the dis- covery could make commercially viable luminescent solar concentrators a reality, especially because the design enhances performance while using the same number of quantum dots, therefore without being more costly.
A team of researchers at the University of Califor- nia, Merced, has redesigned luminescent solar con- centrators to be more efficient at sending sunlight to solar cells. “We tweaked the traditional flat design for luminescent solar concentrators and made them
R. H. Inman, G. V. Shcherbatyuk, D. Medvedko, A. Gopinathan, and S. Ghosh: Cylindrical luminescent so- lar concentrators with near-infrared quantum dots, In: Optics Express, Vol. 19, Issue 24, Pages 24308-24313, DOI:10.1364/OE.19.024308: http://dx.doi.org/10.1364/OE.19.024308