How Graphene Is Changing Photonics
By Emily Newton
Today’s technology moves quickly and the hype around it grows even faster. As such, it can be difficult to sort the buzzwords and fads from the innovations of actual substance. The widely touted applications of graphene are a great example.
Scientists first discovered graphene in 2004. Six years later, they won a Nobel Prize for it. But since then, the material has yet to disrupt industries the way it seemed it would. That could finally be changing. Despite a slow start, graphene is finally reaching a point where it could transform photonics.
What Is Graphene?
Before diving into graphene’s applications in photonics, it helps to understand what exactly it is. Graphene is a hexagonal mesh of carbon just one atom thick. As simple as that sounds, this tiny structure can give carbon some impressive properties.
Most notably, graphene is one of the strongest materials in the world relative to its mass. Despite being one million times thinner than human hair, it’s stronger than steel and diamonds. Being so thin also means it’s highly flexible without compromising that strength.
Graphene is a great conductor of both heat and electricity. It has unique photonic properties, too. It can absorb and refract light and interact with many different light wavelengths. Given all these characteristics, it’s easy to see why the world was so excited about it when it emerged 20 years ago.
The Long Road To Viable Graphene Applications
So why hasn’t graphene changed the world yet? It’s mostly a matter of manufacturing complexity. Turning graphite into a single layer of carbon atoms is difficult. The conventional method is to peel graphite layers until one is small enough, but this takes time, generates considerable waste, and typically only produces a small flake of graphene.
This complexity has made it difficult for graphene manufacturing to scale. While the world has managed to produce thousands of tons of carbon nanotubes and other graphene structures annually, the time and expense involved have kept them to niche applications.
Recent breakthroughs in graphene manufacturing methods are starting to turn things around. Some facilities have adapted processes they used to make other materials to mass-produce graphene, producing enough to make 150,000 devices daily.
As manufacturers are finding more cost-effective and scalable ways to make graphene, the market is showing signs of strong growth. Reports predict annual growth rates to range between 20% and 50% over the next few years. That could mean it’s finally time for this technology to make the impact people thought it would 20 years ago.
Applications Of Graphene In Photonics Today
As this material becomes more accessible, it could mean big changes for the photonics industry. Here are a few of the most exciting applications of graphene in photonics.
Advanced Light Detection
Graphene’s ability to absorb and refract light across the entire spectrum makes it a game-changing tool for light detection. This is particularly helpful in medical and lab applications. Graphene is so sensitive that it can accurately measure the mass of a single protein and — more importantly — do so at room temperature, something normal light sensors can’t do.
It’s worth noting that graphene also responds to light outside of the visible spectrum. That means it could lead to ultra-lightweight infrared sensors for compact night vision cameras, self-driving cars, or wearable medical devices.
Transparent Circuitry
Transparent transistors are another groundbreaking application of graphene in photonics. Graphene is a better conductor of electricity than copper, but thanks to interlayer spacing twice that of graphite and its remarkable thinness, it’s entirely see-through. As a result, electronics companies can use it to create electric circuits or light-emitting electrodes on transparent surfaces.
Smart glass is the most obvious application here. Graphene-based circuits and LEDs could bring smartphone functionality to a transparent screen. Imagine a house where residents can project images or smart home controls on their windows. Clear phones and discreet wearables could also become a reality.
Solar Cells
Graphene also has big implications for renewable energy. More specifically, it can make solar cells more efficient. This material’s high conductivity and low temperatures mean it can raise the efficiency of solar cells from 14.8% to over 45% in some cases. It also can act as a moisture barrier to make solar power more dependable in high humidity.
Combining these graphene applications with those in transparent circuitry shows promise, too. Building solar cells from graphene could lead to efficient, clear solar glass. Transparent solar panels could bring emissions-free electricity to more homes and even help power car electronics.
Optical Communication
The communications industry also can benefit from photonics applications of graphene. Fiber optics have already revolutionized internet services by enabling speeds in the thousands of megabits per second. Graphene’s light sensitivity could make these networks even faster.
Early tests show that graphene cables can achieve transmission speeds up to 18 times faster than conventional fiber. That kind of connectivity could enable mass Internet of Things adoption in heavy industries or streamline international data transfers.
Graphene Applications Are The Future Of Photonics
Despite being discovered two decades ago, graphene is still a new technology in terms of its usage. Businesses have barely scraped the surface of what this material can do. Now that it’s finally possible to mass-produce graphene, the photonics industry could be on the verge of a revolution.
These applications will likely take time to reach their full disruptive potential. Still, it’s an exciting time for the photonics industry, and preparing for this shift now could help companies soar in the future.