Graphene may gain an 'on-off switch,' adding semiconductor to long list of material's achievements

Jun 17, 2011
Graphene is illuminated by a laser field (artist image). Credit: Luis E. F. Foa Torres

A team of researchers has proposed a way to turn the material graphene into a semiconductor, enabling it to control the flow of electrons with a laser "on-off switch".

Graphene is thinnest and strongest material ever discovered. It's a layer of only one-atom thick, but 200 times stronger than steel. It also conducts electricity extremely well and heat better than any other known material. It is almost completely transparent, yet so dense that not even of can penetrate it. In spite of the impressive list of promising prospects, however, graphene appears to lack a critical property -- it doesn't have a "band gap."

A band gap is the basic property of , enabling materials to control the flow of electrons. This on-off property is the foundation of computers, encoding the 0s and 1s of computer languages.

Now, a team of researchers at the National University of Córdoba and CONICET in Argentina; the Institut Catala de Nanotecnologia in Barcelona, Spain; and RWTH Aachen University, Germany; suggest that illuminating graphene with a mid-infrared laser could be a key to switch off conduction, thereby improving the possibilities for novel optoelectronic devices.

In an article featured in Applied Physics Letters, the researchers report on the first atomistic simulations of electrical conduction through a micrometer-sized graphene sample illuminated by a laser field. Their simulations show that a laser in the mid-infrared can open an observable in this otherwise gapless material.

"Imagine that by turning on the light, graphene conduction is turned off, or vice versa. This would allow the transduction of optical into electrical signals," says Luis Foa Torres, the researcher leading this collaboration. "The problem of interacting with radiation is also of current interest for the understanding of more exotic states of matter such as the topological insulators."

Explore further: Carbyne morphs when stretched: Calculations show carbon-atom chain would go metal to semiconductor

More information: The article, "Tuning laser-induced band gaps in graphene," by H. Calvo, H. Pastawski, S. Roche, and L. Foa Torres appears in Applied Physics Letters. See: apl.aip.org/resource/1/applab/v98/i23/p232103_s1

Provided by American Institute of Physics

4.9 /5 (17 votes)

Related Stories

Two graphene layers may be better than one

Apr 27, 2011

(PhysOrg.com) -- Researchers at the National Institute of Standards and Technology have shown that the electronic properties of two layers of graphene vary on the nanometer scale. The surprising new results ...

Water could hold answer to graphene nanoelectronics

Oct 26, 2010

Researchers at Rensselaer Polytechnic Institute developed a new method for using water to tune the band gap of the nanomaterial graphene, opening the door to new graphene-based transistors and nanoelectronics.

Light-speed nanotech: Controlling the nature of graphene

Jan 21, 2009

Researchers at Rensselaer Polytechnic Institute have discovered a new method for controlling the nature of graphene, bringing academia and industry potentially one step closer to realizing the mass production ...

Toward a better understanding of bilayer graphene

Oct 26, 2010

(PhysOrg.com) -- "Graphene is a very exciting material with a number of interesting possibilities, including for use in electronic devices," Pablo Jarillo-Herrero tells PhysOrg.com. "However, all graphene system ...

Damaging graphene to create a band gap

Nov 22, 2010

(PhysOrg.com) -- "Graphene offers a lot of interesting potential applications for nanoelectronics," Florian Banhart tells PhysOrg.com, "but there is no band gap. This is a well-known problem. Without the band gap, switch ...

Recommended for you

PPPL studies plasma's role in synthesizing nanoparticles

17 hours ago

DOE's Princeton Plasma Physics Laboratory (PPPL) has received some $4.3 million of DOE Office of Science funding, over three years, to develop an increased understanding of the role of plasma in the synthesis ...

User comments : 0