A nanosensor to identify vapors based on a graphene-silicon heterojunction Schottky diode

July 11, 2014
ICREA Research Professor Arben Merkoçi

Among other carbon-based nanomaterials, graphene represents a great promise for gas sensing applications. In 2009 the detection of individual gas molecules of NO[sub]2[/sub] adsorbed onto graphene surface was reported for the first time. This initial observation has been successfully explored during the recent years. The Nanobioelectronics & Biosensors Group at Institut Català de Nanociència i Nanotecnologia (ICN2), led by ICREA Research Professor Arben Merkoçi, published in Small a work showing how to use a Graphene/Silicon Heterojunction Schottky Diode as a sensitive, selective and simple tool for vapors sensing. The work was developed in collaboration with researchers from the Amirkabir University of Technology (Tehran, Iran).

The Graphene/Silicon heterojunction Schottky is fabricated using a silicon wafer onto which Cr and Au were deposited to form the junction between graphene and silicon (see the attached figure). The adsorbed molecules change the local carrier concentration in graphene, which yields to the changes in impedance response. The vapors of the various chemical compounds studied change the impedance response of Graphene/Silicon heterojunction Schottky diode. The relative impedance change versus frequency dependence shows a selective response in gas sensing which makes this characteristic frequency a distinctive parameter of a given vapor.

The device is well reproducible for different concentrations of phenol vapor using three different devices. This based device and the developed detection methodology could be extended to several other gases and applications with interest for environmental monitoring as well as other industries.

Explore further: Writing graphene circuitry with ion 'pens'

More information: Small. 2014 Jun 30. DOI: 10.1002/smll.201400691.

Related Stories

Writing graphene circuitry with ion 'pens'

March 27, 2012

The unique electrical properties of graphene have enticed researchers to envision a future of fast integrated circuits made with the one-carbon-atom-thick sheets, but many challenges remain on the path to commercialization. ...

Graphene decoupling of organic/inorganic interfaces

June 19, 2012

(Phys.org) -- Cryogenic ultrahigh vacuum scanning tunneling microscopy (STM) was employed by researchers in the Center for Nanoscale Materials Electronic & Magnetic Materials & Devices Group at the Argonne National Laboratory ...

High quality three-dimensional nanoporous graphene

May 5, 2014

Three-dimentional (3D) nanoporous graphene with preserved 2D Dirac electronic characters was successfully synthesized by Dr. Yoshikazu Ito and Prof. Mingwei CHEN at Advanced Institute for Materials Research (AIMR), Tohoku ...

Resonant energy transfer from quantum dots to graphene

May 22, 2014

Semiconductor quantum dots (QDs) are nanoscale semiconductors that exhibit size dependent physical properties. For example, the color (wavelength) of light that they absorb changes dramatically as the diameter decreases. ...

A new way to make sheets of graphene

May 23, 2014

Graphene's promise as a material for new kinds of electronic devices, among other uses, has led researchers around the world to study the material in search of new applications. But one of the biggest limitations to wider ...

Recommended for you

An engineered surface unsticks sticky water droplets

August 31, 2015

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets ...

Electrical circuit made of gel can repair itself

August 25, 2015

(Phys.org)—Scientists have fabricated a flexible electrical circuit that, when cut into two pieces, can repair itself and fully restore its original conductivity. The circuit is made of a new gel that possesses a combination ...

Scientists grow high-quality graphene from tea tree extract

August 21, 2015

(Phys.org)—Graphene has been grown from materials as diverse as plastic, cockroaches, Girl Scout cookies, and dog feces, and can theoretically be grown from any carbon source. However, scientists are still looking for a ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Rosser
not rated yet Jul 11, 2014
Is this the right illustration for this article? It looks like a graphene grain boundary illustration. No silicone anywhere!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.