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Could Lasers Enhance Solar Cell Efficiency?

April 16th, 2015

Making solar power more efficient, and therefore more cost effective, is a vital goal currently being worked on by engineers throughout the industry. In this era of climate change, finding ways to lessen the carbon footprint caused by power generation offers potential hope for a better planet. The prospect of generating more of our electricity from renewable sources like solar, wind, and water is a goal shared by many engineers.

Scientists at Singapore’s Agency for Science, Technology and Research (A*STAR) are working on a system that uses lasers to improve the efficiency of the individual solar cells used in solar power arrays. This promising research might revolutionize the industry and make solar power a viable economic option for widespread power generation. Let’s take a closer look.

Using Lasers to Transform Silicon

A*STAR’s research is focused on the effects produced by a laser when processing silicon solar cells. Scientists noted that laser processing creates rippling in the silicon. In short, this rippling decreases the reflectivity of the silicon, allowing the resultant solar cells to absorb more sunlight.

A uniform nanoscale ripple pattern etched on solar cell silicon and using a femtosecond laser beam offers researchers the chance to make a breakthrough compared to earlier efforts where the pattern wasn’t deep enough to significantly affect the silicon’s reflectivity. Laser processing generally leaves the internal structure of the silicon unchanged, but the use of the femtosecond laser made the vital difference when it comes to the deepness of the etched ripples.

Xincai Wang, a scientist with A*STAR commented on his team’s efforts. “This increase in depth can substantially reduce light reflection and improve the light-trapping ability of the ripple structure. Hence, if the structure is used in photovoltaic devices, more light will be trapped within the structure, thereby enhancing the device efficiency,” said Wang.

Deeper Ripples at the Scale of Nanometers

A*STAR’s team etched ripples 300 nanometers deep using the new technique with the femtosecond laser. That distance is three times deeper than their previous attempts. Most importantly, this method is relatively simple and inexpensive, which raises the hope for easy adoption of the technology once it is commercialized.

These ripples make a significant difference in the reflectivity of the silicon – dropping it from 39.7 percent to 12.5 percent. Light absorption of the material improved by a factor of 41 percent. In addition to the world of solar power, A*STAR’s research may also impact the light emitting diode (LED) industry.

If these kinds of research innovations inspire you to further your engineering career, talk to the experts at The Talley Group. As one of the foremost engineering staffing agencies in Washington State, we are also a great source for the best Seattle engineering jobs. Schedule some time with us at your earliest convenience.

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