Uniaxial strain on graphene: Raman spectroscopy study and band-gap opening.
Graphene was deposited on a transparent and flexible substrate, and tensile strain up to approximately 0.8% was loaded by stretching the substrate in one direction. Raman spectra of strained graphene show significant red shifts of 2D and G band (-27.8 and -14.2 cm(-1) per 1% strain, respectively) because of the elongation of the carbon-carbon bonds. This indicates that uniaxial strain has been successfully applied on graphene. We also proposed that, by applying uniaxial strain on graphene, tunable band gap at K point can be realized. First-principle calculations predicted a band-gap opening of approximately 300 meV for graphene under 1% uniaxial tensile strain. The strained graphene provides an alternative way to experimentally tune the band gap of graphene, which would be more efficient and more controllable than other methods that are used to open the band gap in graphene. Moreover, our results suggest that the flexible substrate is ready for such a strain process, and Raman spectroscopy can be used as an ultrasensitive method to determine the strain.
Ni
Zhen Hua
ZH
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
Yu
Ting
T
Lu
Yun Hao
YH
Wang
Ying Ying
YY
Feng
Yuan Ping
YP
Shen
Ze Xiang
ZX
D002244:Carbon / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D016011:Normal Distribution; D011093:Polyethylene Terephthalates / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
D037742:Nanotubes, Carbon; D011093:Polyethylene Terephthalates; D002244:Carbon; D012822:Silicon Dioxide; D012825:Silicon