November 25 2017 by Ryan Deschner
The “Glaring” Problem with Using Devices Outdoors
If you have ever taken your smartphone or laptop outside to read or get some work done on a beautiful sunny day, then you are familiar with the struggle: you might tilt the screen downward or try to block the sunlight with your hand, but you cannot escape the glare making it nearly impossible to see the screen. Fortunately for the millions of smartphone and laptop users around the world, researchers at the Center for Functional Nanomaterials (CFN) at Brookhaven National Laboratory have developed a solution: nanostructured glass.
Nanocone Arrays to the Rescue
While it sounds strange that etching tiny structures on your device’s screen is a good idea, it turns out that nanotechnology can provide a practical solution to reducing glare in direct sunlight. The key is to minimize the amount of light that is naturally reflected by the surface of the glass. To reduce glare currently, thin-film anti-reflective coatings (ARCs) are often applied to the surface of windows or screens, however, these films eventually degrade or are easily damaged, limiting their long-term effectiveness. To avoid this degradation, researchers at CFN are developing a method for etching nanocones 300 nm in height into glass that reflect only a very small amount of light. In one experiment, nanocone textured reflected less than 0.2% of incoming red-colored light. As opposed to a scratch-prone film, the nanotextured glass surface is more resistant to damage, and may end up replacing thin-film ARCs as the go-to technique for reduced-glare on windows and device screens.
Nanocone coating reduces reflected light from glass surfaces, greatly eliminating glare.
Further Product Applications
This technology is a welcome advance for those seeking to use their devices outdoors, however, there are other industrial implications for nanocone glare reducing surfaces. The research team is looking to translate nanotexturing to enhance the performance of solar cells for renewable energy applications. A major source of inefficiency in solar energy production comes from solar panel damage after long-term exposure to sunlight. The CFN team tested the electricity-generation performance of uncovered solar cells versus cells fitted with nanotextured glass as well as against cells with non-textured glass. They found that the nanotextured surface generated the same amount of electrical energy as the uncovered solar cell, and that the cells with the nanotextured glass cover could withstand three times more optical energy per unit area before exhibiting surface damage than cells coated with non-textured commercially available ARCs . These results suggest a viable means to increase the efficiency of solar panels and prolong their usable life, which would have great benefits for the solar industry and help reduce dependence on non-renewable energy sources.
Andreas C. Liapis, Atikur Rahman, Charles T. Black. Self-assembled nanotextures impart broadband transparency to glass windows and solar cell encapsulants. Applied Physics Letters, 2017; 111 (18): 183901 DOI: 10.1063/1.5000965