With a carbon footprint that’s 20 times less than coal and 12 times less than natural gas, solar power is crucial to the clean energy transition. Producing solar panels requires lasers to scribe photovoltaic material onto each solar cell. But, as solar panel designs become more precise—reducing production costs and improving efficiency—it’s becoming increasingly tricky for manufacturers to produce solar panels using traditional laser methods.
Ultra-Short-Pulse (USP) lasers might have the solution. These ultra-precise lasers use light beams so short that they don’t burn the surrounding material. This results in higher first-time accuracy, which tests show can cut both waste and energy use by 90 percent in manufacturing applications. Beyond scribing solar cells (creating thin lines in the material), USP lasers can produce semiconductor circuit boards and flat panel displays (i.e. device screens). These have use cases in electronics, aerospace and medical technology.
At the Fraunhofer Institute for Laser Technology (Fraunhofer ILT) in Aachen, a team of researchers, led by Martin Osbild, is working on an EU-funded research project called METAMORPHA. The project is investigating the environmental benefits of USP lasers and considering how they could replace micro-machining manufacturing.
Less chemicals, no additional coatings and reduced wear and tear
The pulses of light from a USP laser last between a trillionth and a quadrillionth of a second. Because they are so incredibly brief, these light pulses cut extremely precisely, without burning or damaging the surrounding material. The cut material doesn’t melt, but transitions instantly from a solid to a gas. This method, known as cold-processing, is especially useful for heat-sensitive materials.
The cuts left by traditional lasers require chemicals to smooth out the material’s surface. With USP lasers, this manufacturing step can be skipped entirely, because the precise cuts don’t leave any trace. While traditional manufacturing methods add coatings to products after they’ve been cut by a laser, USP lasers can cut directly into surface coatings. Because the laser machine never touches the materials, it won’t experience wear and tear in the same way as other cutting tools. What’s more, manufacturers can use the same laser to produce multiple products, reducing the need for different cutting tools for each product design.
USP lasers are already minimising chemical use and improving efficiency in manufacturing. Using 3D sensors and machine learning in conjunction with USP lasers will allow manufacturers to further optimise their efficiency, reduce waste and improve designs. “Laser technologies are set to become more widely adopted as manufacturers across industries continue seeking ways to improve efficiency and performance while reducing environmental impact,” according to photonics and laser surface engineering specialist Professor Andrés Lasagni, who was involved in a preceding EU-research project on USP lasers.
High costs and power requirements—but huge potential
Unfortunately, the ultra-precise technology required for USP lasers doesn’t come cheap. As well as high acquisition costs for manufacturers, USP lasers also have high power requirements. Current commercial systems operate at 200 to 300 watts, but the METAMORPHA team is testing a 1-kilowatt USP laser. This would allow USP lasers to efficiently run on an industrial scale.
In the case of solar panel manufacturing, which, according to the IEA, produced more than 51.9 million tonnes of CO2 in 2021, improving efficiency and cutting waste by up to 90 percent would avoid a significant amount of CO2 emissions. Replicate these savings across a variety of industries, and the potential of these ultra-fast, ultra-precise beams of light becomes visible to the naked eye.
