“This new type of ‘broadband’ light emitter can be integrated into chips and will pave the way towards the realization of atomically thin, flexible, and transparent displays, and graphene-based on-chip optical communications.”
Led by Young Duck Kim, a postdoctoral research scientist in James Hone’s group at Columbia Engineering, a team of scientists from Columbia, Seoul National University (SNU), and Korea Research Institute of Standards and Science (KRISS) reported today that they have demonstrated—for the first time—an on-chip visible light source using graphene, an atomically thin and perfectly crystalline form of carbon, as a filament. They attached small strips of graphene to metal electrodes, suspended the strips above the substrate, and passed a current through the filaments to cause them to heat up. The study, “Bright Visible Light Emission from Graphene,” is published in the Advance Online Publication (AOP) on Nature Nanotechnology‘s website on June 15.
“We’ve created what is essentially the world’s thinnest light bulb,” says Hone, Wang Fon-Jen Professor of Mechanical Engineering at Columbia Engineering and coauthor of the study. “This new type of ‘broadband’ light emitter can be integrated into chips and will pave the way towards the realization of atomically thin, flexible, and transparent displays, and graphene-based on-chip optical communications.”
Creating light in small structures on the surface of a chip is crucial for developing fully integrated “photonic” circuits that do with light what is now done with electric currents in semiconductor integrated circuits. Researchers have developed many approaches to do this, but have not yet been able to put the oldest and simplest artificial light source—the incandescent light bulb—onto a chip. This is primarily because light bulb filaments must be extremely hot—thousands of degrees Celsius—in order to glow in the visible range and micro-scale metal wires cannot withstand such temperatures. In addition, heat transfer from the hot filament to its surroundings is extremely efficient at the microscale, making such structures impractical and leading to damage of the surrounding chip.
By measuring the spectrum of the light emitted from the graphene, the team was able to show that the graphene was reaching temperatures of above 2500 degrees Celsius, hot enough to glow brightly. “The visible light from atomically thin graphene is so intense that it is visible even to the naked eye, without any additional magnification,” explains Kim, first and co-lead author on the paper.
Interestingly, the spectrum of the emitted light showed peaks at specific wavelengths, which the team discovered was due to interference between the light emitted directly from the graphene and light reflecting off the silicon substrate and passing back through the graphene. Kim notes, “This is only possible because graphene is transparent, unlike any conventional filament, and allows us to tune the emission spectrum by changing the distance to the substrate.”
the substrate or the metal electrodes is due to another interesting property: as it heats up, graphene becomes a much poorer conductor of heat. This means that the high temperatures stay confined to a small “hot spot” in the center.
“At the highest temperatures, the electron temperature is much higher than that of acoustic vibrational modes of the graphene lattice, so that less energy is needed to attain temperatures needed for visible light emission,” Myung-Ho Bae, a senior researcher at KRISS and co-lead author, observes. “These unique thermal properties allow us to heat the suspended graphene up to half of the temperature of the sun, and improve efficiency 1000 times, as compared to graphene on a solid substrate.”
The team also demonstrated the scalability of their technique by realizing large-scale of arrays of chemical-vapor-deposited (CVD) graphene light emitters.
Read more: World’s Thinnest Light Bulb—Graphene Gets Bright!
The Latest on: Broadband light emitter
[google_news title=”” keyword=”Broadband light emitter” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Broadband light emitter
- 15 Best LED Light Therapy Masks to Turn the Clock Back on Agingon June 8, 2023 at 11:34 am
Developed by NASA (yes!) as a method for stimulating plant growth and treating astronaut wounds, LED light therapy has since been adopted by beauty care professionals for skincare treatments. It works ...
- Keep the family cool this summer with Virgin Media’s fastest speeds and ultra-reliable WiFion June 2, 2023 at 4:56 am
Keep the family cool this summer with fastest speeds and unbeatable reliability on Virgin Media WiFi, WiFi 6, Intelligent WiFi technology and more.
- Surface plasmon polaritons launched by nano-emitters are imaged in the near fieldon May 30, 2023 at 5:00 pm
(Courtesy: Deep Jariwala/University of Pennsylvania) Light emitters made from 2D and quasi-2D materials are currently of great interest in nano-optoelectronics because their lack of dielectric ...
- Sticking to Light-Cure Adhesiveson May 30, 2023 at 5:00 pm
and offer slight amounts of residual light in nearby wavelengths (±15 nm). LED systems are efficient because they do not emit excess and unnecessary broadband light and heat/infrared energy. LEDs ...
- Beating the heat: These plant-based iridescent films stay cool in the sunon May 30, 2023 at 2:58 pm
Scientists from the University of Cambridge have developed an innovative new plant-based film that gets cooler when exposed to sunlight, making it ideal for cooling buildings or cars in the future ...
- Progressive quantum leaps—high-speed, thin-film lithium niobate quantum processors driven by quantum emitterson May 24, 2023 at 6:56 am
They accomplished this by using the circuits to regulate and facilitate the function of quantum states of light emitted from ... use of deterministic quantum emitters by rotating streams of ...
- The Other BBL Treatment That's Harming Melanated Skinon May 13, 2023 at 5:38 am
Monique Diaz Doolin learned this the hard way after receiving broadband light (BBL) therapy, offered to her as a no-risk "facial" by an aesthetician at a medical spa. Also known as a "photofacial ...
- High-speed and On-silicon-chip Graphene Blackbody Emitterson May 2, 2023 at 5:00 pm
High-speed light emitters integrated on silicon chips can enable novel architectures for silicon-based optoelectronics. However, compound-semiconductor-based light emitters face major challenges for ...
- Light-Emitting Diodeson March 2, 2023 at 8:55 pm
white-light emitters with wavelength-converting phosphor materials, optical reflectors, and spontaneous recombination in resonant-cavity structures are discussed in detail. With exercises, solutions, ...
- Spontaneous-emission control by photonic crystals and nanocavitieson June 29, 2021 at 12:54 am
It has been clearly demonstrated that the spontaneous emission from light emitters embedded in photonic crystals can be suppressed by the so-called photonic bandgap, whereas the emission ...
via Bing News