The National Renewable Energy Laboratory (NREL) has built a robot that will help the R&D of thin film solar cells, analyzing possible defects faster and more accurate than any other existing system. It is called the PDIL (Process Development and Integration Laboratory).
The robot’s performance is so high that it can build a semiconductor on a 6-inch square plate of glass, plastic or flexible metal in only about 35 minutes. The entire process is automated and the working chamber vacuumed, so the researchers don’t have to wear protective clothes.
NREL plans to build another five of these robots, each one doing a different task: stand-alone characterization, integrated characterization, atmospheric processing and the one that uses Copper Indium Gallium diSelenide (CIGS) as the semiconductor in solar cell. The latest robot will work with cadmium-telluride solar cells.
Companies will be able to make reservations for the robots, and test their newest technologies on them, to gain the best efficiency in their solar panels.
The whole goal is dollars per watt,” NREL scientist Ingrid Repins said. President Obama has set a goal that solar energy become cost-competitive with coal and other fossil fuels by 2015. “The gap is closing,” Repins said. “We’re getting closer. Already, First Solar is saying that for a large installation in southern California where electricity prices are relatively high, they are at parity now.”
NREL has already developed CIGS solar cells in the past, and they had an efficiency of almost 20 percent, but that was obtained only in lab conditions. They will further use the newly devised machinery to improve the fabrication technology, so the 20 percent will also be available in industrial building conditions.
Repins envisions that in a few years companies can roll out kilometer-long sheets of solar cells and still achieve 16 percent efficiency – even as they strive to use the least expensive materials and put an emphasis on speed.
The CIGS PDIL tool also was designed to do basic research and development on materials. The ultra-high vacuum environment allows scientists to study the role of impurities and defects, as well as what happens when the metals are deposited at the fast rate demanded by industry. That knowledge will help researchers develop analytical tools for quality control and to test for new plate materials.
The purpose of the PDIL is to improve the speed, quality and price of solar cells, which is something the industry is craving for, so NREL’s investment is not in vain – it will surely yield magnificent results during the next few years.