Cameras, solar panels, biosensors, and fiber optics are technologies that rely on photodetectors, or sensors that convert light into electricity. With the shrinking size of their component semiconductor chips, photodetectors are becoming more efficient and affordable. However, current materials and manufacturing methods are constraining miniaturization, forcing trade-offs between size and performance.
[...] Manufacturing uniform, extremely thin, high quality photonic semiconductor films of material other than silicon would make semiconductor chips more efficient, applicable, and scalable.
One-atom-thick materials generally take the form of a lattice, or a layer of geometrically aligned atoms that form a pattern specific to each material. A superlattice is made up of lattices of different materials stacked upon one another. Superlattices have completely new optical, chemical and physical properties which make them adaptable for specific applications such as photo optics and other sensors.
The team at Penn Engineering made a superlattice, five atoms thick, of tungsten and sulfur (WS2).
[...] Their superlattice design is not only extremely thin, making it lightweight and cost effective, it can also emit light, not just detect it.
"We are using a new type of structure in our superlattices that involves exciton-polaritons, which are quasi-state particles made of half matter and half light," says Lynch. "Light is very hard to control, but we can control matter, and we found that by manipulating the shape of the superlattice, we could indirectly control light emitted from it. This means our superlattice can be a light source. This technology has the potential to significantly improve lidar systems in self-driving cars, facial recognition and computer vision."
Being able to both emit and detect light with the same material opens the door for more complicated applications.
"One current technology that I can see our superlattice being used for is in integrated photonic computer chips which are powered by light," says Lynch. "Light moves faster than electrons, so a chip powered by light will increase computing speed, making the process more efficient, but the challenge has been finding a light source that can power the chip. Our superlattice may be a solution there."
Applications for this new technology are diverse and will likely include high-tech robotics, rockets, and lasers. Because of the wide range of applications for these superlattices, the scalability is very important.
Journal Reference:
Kumar, Pawan, Lynch, Jason, Song, Baokun, et al. Light–matter coupling in large-area van der Waals superlattices, Nature Nanotechnology, 2022.
DOI: 10.1038/s41565-021-01023-x
(Score: 0) by Anonymous Coward on Friday April 22 2022, @07:14PM
Don't know if the editors are aware, but there is a illegal spam mod on this comment. [soylentnews.org]
For the future of SN, I trust it will be removed quickly.
(Score: 0) by Anonymous Coward on Friday April 22 2022, @07:44PM
what's the ERoEI (energy returned on energy invested)? potential to improve on regular solarmodules?