“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
- Bringing Brilliance To Life: The Story Of LED Light Expertson May 8, 2024 at 12:29 pm
In the world of illumination, LED lighting has emerged as a transformative force, revolutionizing how we light up our spaces while significantly reducing energy consumption and environmental impact.
- Biomimetic LEDs inspired by the natural light-emitting mechanisms of fireflieson May 7, 2024 at 2:25 am
A new groundbreaking innovation known as biomimetic LEDs is setting new benchmarks for efficiency and sustainability. Inspired by the captivating natural ...
- The BREAD Collaboration is searching for dark photons using a coaxial dish antennaon May 3, 2024 at 3:50 am
Approximately 80% of the matter in the universe is predicted to be so-called "dark matter," which does not emit, reflect, or absorb light and thus cannot be directly detected using conventional ...
- QLED vs. OLED: Here's the Difference and Why It Matters When You're Buying a TVon May 1, 2024 at 1:29 pm
Quantum dots are microscopic molecules that, when hit by light, emit their own differently colored light. In QLED TVs, the dots are contained in a film, and the light that hits them is provided by ...
- vivo V30 5G review – Smartphone photography at its beston April 28, 2024 at 11:30 pm
We were thoroughly impressed with the vivo V30 5G’s cameras and its Aura Light Portrait module, which is a turbo-charged flash delivering perfect lighting.
- Best light pollution filters for astrophotography 2024on April 26, 2024 at 6:34 am
Two types of filters are available: broadband and narrowband. They work in slightly different ways and offer different results depending on your needs. Narrowband filters allow light from nebulas ...
- Looking to Spruce Up Your Indoor Garden? Here are 7 of the Best Grow Lights For Every Budgeton March 21, 2024 at 6:59 am
Though they're known to emit blue light ... Because it features sunlike broadband full spectrum light, Spider Farmer claims its product "has a significant impact on plant germination, flowering ...
- The life and times of the LED — a 100-year historyon December 23, 2023 at 8:19 pm
The semiconductor light-emitting diode, or LED ... serving the ever-growing demand for broadband telecommunication and Internet. Over the next decade the value of the burgeoning LED market ...
- Light Emitting Diodes (LED) Informationon January 8, 2022 at 3:07 pm
Light emitting diodes (LEDs) are PN junction devices that give off light radiation through electroluminescence when forward biased. They are used as various indicators in aviation, automotive and ...
via Bing News