title: Uniaxial strain on graphene: Raman spectroscopy study and band-gap opening.
abstract: 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.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore.
authors.forename: Zhen Hua
authors.initials: ZH
authors.lastname: Ni
authors.forename: Ting
authors.initials: T
authors.lastname: Yu
authors.forename: Yun Hao
authors.initials: YH
authors.lastname: Lu
authors.forename: Ying Ying
authors.initials: YY
authors.lastname: Wang
authors.forename: Yuan Ping
authors.initials: YP
authors.lastname: Feng
authors.forename: Ze Xiang
authors.initials: ZX
authors.lastname: Shen
mesh_terms: 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
chemical_list: D037742:Nanotubes, Carbon; D011093:Polyethylene Terephthalates; D002244:Carbon; D012822:Silicon Dioxide; D012825:Silicon