Textured surface may boost power output of thin silicon solar cells
Highly purified silicon represents up to 40 percent of the overall costs of conventional solar-cell arrays — so researchers have long sought to maximize power output while minimizing silicon usage. Now, a team at MIT has found a new approach that could reduce the thickness of the silicon used by more than 90 percent while still maintaining high efficiency.The secret lies in a pattern of tiny inverted pyramids etched into the surface of the silicon. These tiny indentations, each less than a millionth of a meter across, can trap rays of light as effectively as conventional solid silicon surfaces that are 30 times thicker.The new findings are being reported in the journal Nano Letters in a paper by MIT postdoc Anastassios Mavrokefalos, professor Gang Chen, and three other postdocs and graduate students, all of MIT’s Department of Mechanical Engineering.“We see...