MIT and Johns Hopkins team manage to make graphene self-fold into 3D shapes

Oct 10, 2017

Researchers with Johns Hopkins University and MIT have shown a way to cause flat sheets of graphene to self-fold into 3D geometric shapes. The group explains how they prepared the sheets and then used heat to cause them to fold. The ability to create 3D objects from sheets of graphene can advance opportunities in fields like sensors, wearables and more.

Graphene can be folded into 3D shapes image

In their work, the researchers developed a micro-patterning technique that leads to the flat graphene sheets bending along predesignated lines when heat is applied, causing the sheet to form into shapes. The new method not only preserves the intrinsic properties of the graphene, but it was also found that the creases can cause a band gap in the graphene, which can be extremely useful.

Researchers manipulate graphene to bring it closer to transistor applications

Aug 30, 2017

Researchers at the U.S. Department of Energy’s Ames Laboratory successfully manipulated the electronic structure of graphene, which may enable the fabrication of graphene transistors that could be faster and more reliable than existing silicon-based transistors.

Ames Lab manipulates graphene image

The researchers were able to theoretically calculate the mechanism by which graphene’s electronic band structure could be modified with metal atoms. The work will guide experimentally the use of the effect in layers of graphene with rare-earth metal ions “sandwiched” (intercalated) between graphene and its silicon carbide substrate. Since the metal atoms are magnetic, the additions can also modify the use of graphene for spintronics.

Researchers develop an efficient and healthy laser-induced graphene foam lighting device

May 19, 2017

Researchers from the Institute of low temperature and structure research in Wroclaw, Poland, developed a new efficient white light source that uses graphene foam excitated by a continuous-wave laser. The laser opens up a bandgap in graphene which results in light emission that ranges from 360nm (UV) or 405nm (visible) to 980nm-1064nm (near-infrared).

Graphene foam based white-light source (wroclaw)

The researchers say that the light spectrum of this device is similar to the spectrum of the sun which is better than current light sources such as LEDs that offer light spectrum with strong peaks (the main problem is the strong blue light emission in LED lighting). This design can achieve a high efficiency (over 200 lm/W), high color rendering index (CRI > 99) and a broadband warm white color. The lifetime depends on the laser, which can be over 10,000 hours.

Valleytronics research advances thanks to bi-layer graphene

Aug 31, 2016

Researchers from Penn State University demonstrated a new device, based on bi-layer graphene, that provides an experimental proof of the ability to control electron-flow by the valley degree of freedom. Valleytronics is a new field of science that aims to create devices that use electron's valley degree of freedom (in a somewhat similar way to Spintronics that aims to do the same with electron spin).

Bi-layer graphene based valleytronics experiment (Penn State)

The device is built from bi-layer graphene. The researchers added an electric field perpendicular to the plane opens a bandgap in the bi-layer graphene, which then enables them to build valleytronics valves in a physical gap present in the device.

Graphene quantum dots and TiO2 exhibit fascinating light harvesting capabilities

Jul 20, 2016

Researchers at Australia's Griffith University have discovered a fascinating mechanism, that may allow the design of a new class of composite materials for light harvesting and optoelectronics. The team has found a quantum-confined bandgap narrowing mechanism, where UV absorption of the graphene quantum dots and TiO2 nanoparticles can easily be extended into the visible light range.

According to the scientists, real life application of this would be high efficiency paintable solar cells and water purification using sun light. In addition, the team states that "this mechanism can be extremely significant for light harvesting. What's more important is we've come up with an easy way to achieve that, to make a UV absorbing material to become a visible light absorber by narrowing the bandgap."