Nav: Home

Seeing the invisible with a graphene-CMOS integrated device

June 05, 2017

Silicon based CMOS (Complementary metal-oxide semiconductors) technology has truly shaped our world. It enables most of the electronics that we rely on today including computers, smartphones and digital cameras. However, to continue the path of progress in the electronics industry new technology must be developed and a key feature of this is the ability to integrate CMOS with other semiconductors. Now, Graphene Flagship researchers from ICFO (The Institute of Photonic Sciences in Barcelona) have shown that it is possible to integrate graphene into a CMOS integrated circuit.

In their paper published in the journal Nature Photonics they combine this graphene-CMOS device with quantum dots to create an array of photodetectors, producing a high resolution image sensor. When used as a digital camera this device is able to sense UV, visible and infrared light at the same time. This is just one example of how this device might be used, others include in microelectronics, sensor arrays and low-power photonics.

"The development of this monolithic CMOS-based image sensor represents a milestone for low-cost, high-resolution broadband and hyperspectral imaging systems" ICREA Professor at ICFO, Frank Koppens, highlights. He assures that "in general, graphene-CMOS technology will enable a vast amount of applications, that range from safety, security, low cost pocket and smartphone cameras, fire control systems, passive night vision and night surveillance cameras, automotive sensor systems, medical imaging applications, food and pharmaceutical inspection to environmental monitoring, to name a few".

These results were enabled by the collaboration between Graphene Flagship Partner Graphenea (a Spanish graphene supplier) and ICFO, within the optoelectronics workpackage of the Graphene Flagship.

By creating a hybrid graphene and quantum dot system on a CMOS wafer using a layering and patterning approach, the Flagship team solved a complex problem with a simple solution. First the graphene is deposited, then patterned to define the pixel shape and finally a layer of PbS colloidal quantum dots is added. The photoresponse of this system is based on a photogating effect, which starts as the quantum dot layer absorbs light and transfers it as photo-generated holes or electrons to the graphene, where they circulate due to a bias voltage applied between two pixel contacts. The photo signal is then sensed by the change in conductivity of the graphene, with graphene's high charge mobility allowing for the high sensitivity of the device.

As Stijn Goossens comments, "No complex material processing or growth processes were required to achieve this graphene-quantum dot CMOS image sensor. It proved easy and cheap to fabricate at room temperature and under ambient conditions, which signifies a considerable decrease in production costs. Even more, because of its properties, it can be easily integrated on flexible substrates as well as CMOS-type integrated circuits."

The commercial applications of this research and the potential for imaging and sensing technology are now being explored in ICFO's Launchpad incubator.

Professor Andrea Ferrari, Science and Technology Officer and Chair of the Management Panel of the Graphene Flagship added: "The integration of graphene with CMOS technology is a cornerstone for the future implementation of graphene in consumer electronics. This work is a key first step, clearly demonstrating the feasibility of this approach. The Flagship has put a significant investment in the system level integration of graphene, and this will increase as we move along the technology and innovation roadmap".

Graphene Flagship

Related Graphene Articles:

Graphene is 3D as well as 2D
Graphene is actually a 3D material as well as a 2D material, according to a new study from Queen Mary University of London.
Conductivity at the edges of graphene bilayers
For nanoribbons of bilayer graphene, whose edge atoms are arranged in zigzag patterns, the bands of electron energies which are allowed and forbidden are significantly different to those found in monolayer graphene.
How to purify water with graphene
Scientists from the National University of Science and Technology 'MISIS' together with their colleagues from Derzhavin Tambov State University and Saratov Chernyshevsky State University have figured out that graphene is capable of purifying water, making it drinkable, without further chlorination.
Decoupled graphene thanks to potassium bromide
The use of potassium bromide in the production of graphene on a copper surface can lead to better results.
1 + 1 does not equal 2 for graphene-like 2D materials
Physicists from the University of Sheffield have discovered that when two atomically thin graphene-like materials are placed on top of each other their properties change, and a material with novel hybrid properties emerges, paving the way for design of new materials and nano-devices.
Graphene's magic is in the defects
A team of researchers at the New York University Tandon School of Engineering and NYU Center for Neural Science has solved a longstanding puzzle of how to build ultra-sensitive, ultra-small electrochemical sensors with homogenous and predictable properties by discovering how to engineer graphene structure on an atomic level.
Graphene on the way to superconductivity
Scientists at HZB have found evidence that double layers of graphene have a property that may let them conduct current completely without resistance.
A human enzyme can biodegrade graphene
Graphene Flagship partners discovered that a natural human enzyme can biodegrade graphene.
Sculpting with graphene foam
Rice University scientists have developed a simple way to produce conductive, three-dimensional objects made of graphene foam.
The photoexcited graphene puzzle solved
A boost for graphene-based light detectors.
More Graphene News and Graphene Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.