With solar cells, thin could be in

Picture source: http://carboncycle2.lbl.gov
INDUSTRIAL ENGINEER – VOLUME 45 NUMBER 10

Pittsburgh researchers work to optimize photonic crystal production
Combining optimization techniques with electrodynamic simulations could yield a new type of thinner , more efficient, low cost solar cell, according to researchers at the University of Pittsburgh by professor of industrial engineering Paul W. Leu and his colleague, electrical and computer engineering Kevin P. Chen.

“We have this new methodology, this new manufacturing process by which we can make very small three-dimensional photonic crystals, three-dimensional nanostructure , over fairly large areas” Leu said. “We’re trying to use this structures to trap light so that you can have very high efficiencies.”

Like atomic crystals that have certain defined electronic properties, photonic crystals have optical properties that allow them to control how light interacts with them, Leu said. The plan is to learn how to produce more efficient solar cells that use less material in the manufacturing process. The nanostructures are so small that one solar cell would contain about 1 trillion units of the photonic crystal.

“We use electro dynamic simulations, which allows us to quickly with predicted accuracy evaluate different photonic crystal structure” Leu said. So we want to integrate optimization methods with simulations so that we can very quickly determine what are promising or optimal structures.

“From the experimental standpoint, our goal is to fabricate 3-D silicon photonic crystal as a proof of concept,” Leu said. “And we’re integrating these electrodynamic simulations with inverse design techniques to see what processes we should use to fabricate the desire structure.”

Electricity that costs less than $1 per peak watt starts becoming competitive with the grid , Leu said, although costs vary by location. Although that is the eventual goal. Leu said the photonic crystal; research is too new to estimate future costs of production and distribution. The Pittsburgh professors hope to turn the exploratory grant into a full proposal where they dig down into the fundamentals, examining the structures’ process and property relationship.