Thursday, December 27, 2012

Cutting graphene using atomic force microscope

In a recent study, atomic force microscope is used to cut the graphene. Cutting forces are also measured with higher single cutting force along armchair direction than zig-zag.

Growth of monolayer Yttria on Graphene !

Researchers have successfully deposited a monolayer of Yttria- a high k dielectric- on graphene under high vacuum conditions. This provides a significant leap for integrating graphene in device architectures.

Sunday, December 23, 2012

Electron energy loss spectroscopy helps in probing single Si atom dopant in graphene

A combination of scanning electron micsroscope (SEM), electron energy loss spectroscopy (EELS) and ab-initio calculations reveal the bonding and electronic structure of single Si atom dopant in graphene.

Tuesday, December 18, 2012

Graphene floats on SiC !

Epitaxial graphene grown on SiC has excellent quality in terms of mobility and is a candidate for microelectronics industry. However, graphene's interaction with SiC disturbs most of the properties. In a recent ACS Nano report, researchers have used oxygen as an intercalant to lift graphene from SiC and opens up ways for  further applications.

Thursday, December 13, 2012

Trilayer graphene as a versatile platform for electron optics and pseudospintronics

Not only single layer graphene rather multilayer graphene has also great promises for nanotechnology. In recent experiments, trilayer graphene is demonstrated as a potential candidate for pseudospintronics and electron optics.

micro-wave induced electrical response leads to spin resonance in epitaxial graphene

Graphene is strongly known for its exotic electronic properties. However, spin properties of graphene are also vitally important for new spintronics based devices. A recent report published in Nature reveals hole spin resonance and zero-field psuedo splitting in epitaxial graphene photoexcited by microwaves.

Thursday, December 6, 2012

Hybridized gold with graphene induces giant Rashba splitting

One of the major focus areas in graphene research is the spintronic applications of graphene. However, this depends on an efficient induction of spin-orbit coupling in graphene

Now, it is demonstrated using angle resolved photo-emission spectroscopy that hybridization between gold (a special configuration) and graphene can lead to enhanced spin-orbit splitting of the order of 100 meV

Photocurrent measurements of supercollision cooling in graphene

Optoelectronic and plasmonic applications of graphene relies on cooling of hot electrons generated after interaction with light. A group of reserachers have studied the nature of this cooling using graphene as a thermometer and explains the findings by invoking supercollision mechanism found recently in graphene.

Undoped graphene helps in detection of supercollision cooling !

The flexibility of changing the Fermi energy level of graphene by a voltage has proven to be a blessing in many applications. Especially  optoelectronics and photonic application of graphene have emerged. 
A new finding reveals the detection of supercollision, i.e. collision of charge carriers with both phonons and impurities, in graphene. The study proves to be useful for bolometric and photo-detection applications of graphene.

Monday, December 3, 2012

Graphene-CNT hybrid for energy storage

A recent work at Rice University has demonstrated the synthesis of graphene-CNT hybrid material. A surface area of as high as >2,000 m2 g−1  has been achieved with an ohmic contact between graphene and CNTs.

Saturday, December 1, 2012

Graphene- recoverable structure under high stresses

Recent high pressure experiments on few layer graphene have demonstrated that graphene possesses most healable structure under high stresses.

Tuesday, November 20, 2012

Graphene's excellent conductivity is being utilized in numerous applications. In a recent experimental study, graphene's role in photoelectrochemical applications is invoked. The efficient separation of photo-generated electron hole pairs at iron oxide/graphene heterojunctions resulted in an improved water splitting efficiency.

Thursday, November 1, 2012

light induced doping in CVD graphene

A recent work by Rice University scientists has revealed that graphene can be doped optically. This has been achieved by exploiting plasmon resonance of metal nanoparticle, arranged in a well ordered manner at nanoscale, deposited on single layer graphene. 
The study opens up doors for plasmonic and optoelectronic applications of graphene.

Wednesday, October 31, 2012

Computational studies reveal graphene's role in water desalination by making pores of appropriate size to separate water, sodium and chloride ions.
Researchers at MIT have used CVD graphene to selectively filter molecules. This has been attributed to the intrinsic defects in CVD graphene. Graphene takes one more leap for energy and water solutions.

Monday, October 29, 2012

Gapless Graphene modulates THz waves

For electronics industry, zero band gap of graphene has been a curse regardless of astonishing carrier mobility and optical transparency. However, gapless graphene seems to be a boon for optical transmission in THz range. This is all because of broadband absorption by graphene. 
Researchers at University of Notre Dame have demostrated an unseen capability of graphene as THz wave modulator.

Thursday, October 25, 2012

A new study has revealed the formation of mm sized graphene crystals by chemical vapor deposition. The study demonstrates the capability of CVD process for graphene growth.

Defect engineering of Graphene

Controlling the defects in graphene is a very challenging task which when circumvented can provide defected graphene with more number of applications. Researchers at University of Oxford have used electron beam to create defects in graphene in a controlled manner. This can pave the way for graphene research based on atomic defects.

Monday, October 22, 2012

Graphene has shown great promise in upcoming plasmonic future where photons can be electrically controlled. However, this requires designing appropriate photonic materials where graphene can be used an active material. 
In a recent report in Nature Materials, it is indeed demonstrated that graphene, in conjunction with the metamaterial, can modulate both the amplitude and phase of the transmitted waves.

Tunable graphene lens

Graphene is known to exhibit a broad absorption peak at around 4.6 eV. This is attributed to resonant excitonic effects due to electron-hole interaction in the pi and pi star bands. Feeding on this extraordinary property of this single atomic layer, recent theoretical work has demonstrated that graphene layers can act as frequency tunable subwavelength imaging device in a proper configuration of a lens.

Saturday, October 20, 2012

STM studies on a single graphene nanoribbon

Researchers have studied a single graphene nanoribbon molecule to study voltage dependence conductance. This could start the graphene based molecular nanoelectronics.

Wednesday, October 17, 2012

Flexible graphene Li ion batteries

Scientists in China have demonstrated the use of graphene in flexible Li ion batteries with enhanced charge and discharge rates. They claim it is light weight too !

Sunday, October 14, 2012

Engineering graphene nanopores for biosensing!

Researchers have used in-situ electron irradiation and heating in a TEM chamber to manipulate the size of graphene nanopores. This enables the shrinkage or widening of a graphene nanopore. The nanopores can be shrunk to the sizes small enough to thread a single DNA strand. This will help in DNA sequencing.
Graphene is a flourishing material which has significant impact on biomedical industry.

Sunday, October 7, 2012

Scratching CVD growth of graphene- Good papers to read for newcomers in the field

1) First report on large area growth of graphene films on Ni catalysts

2) Large area growth of graphene on Cu catalysts

3) Large area few layer graphene films directly grown on arbitrary substrates

4) Improved graphene transfer process

5) Wafer scale synthesis and transfer of graphene

Thursday, October 4, 2012

Grahene metamaterials for photonic memory

Graphene's role in plasmonic materials is boosted by the current report in Nature. It is demonstrated that gate controlled graphene metamaterials can exhibit photonic memory effects.

Wednesday, October 3, 2012

Highly transparent nonvolatile resistive memory devices based on graphene

Transparent electronic memory gets a leap with the utilization of graphene as a transparent electrode  Not only transparency, it gets flexibility also by using flexible substrates.

Tuesday, October 2, 2012

Graphene tunnel barriers for spin injection

In a recent report, published in nature nanotechnology, graphene has been used a tunnel barrier for low resistance spin injection into silicon. This is attributed to chemical inertness and high conductivity of graphene.

Sunday, September 30, 2012

Nanoreactor theory of graphene synthesis by chemical vapor deposition

Researchers at Rice University (an active group working on graphene) demonstrate that every atom counts in graphene formation using DFT calculation of CVD process. They have highlighted the importance of carbon dimer for faster and better quality graphene growth. Overall, the study reveals the importance of mostly favored low energy paths for graphene formation.

Friday, September 28, 2012

Wetting behavior of graphene gets a new look !

Recent findings reveal a complex picture of wetting behavior of graphene.

Graphene dispersion velocity

Graphene has provided a great physical avenue for fundamental research. Now, its two dimensional structure, a true surface, has made it possible to study electron-electron interactions far away from Fermi energy level.

Saturday, September 15, 2012

Graphene- A Carbon Avatar termed as an Olympic Material

The three dimensional world around us has shown great potential for human kind and when the dimensionality of materials is scaled down to lower dimensions, an another world has been explored by researchers. In the world of two dimensional materials, graphene stands as a conquering queen which paved the way to the astonishing 2D world and aroused flooding interest in these materials. The 2D materials hold great promising future applications in nanotechnology.