title: Biaxial compressive strain engineering in graphene/boron nitride heterostructures.
abstract: Strain engineered graphene has been predicted to show many interesting physics and device applications. Here we study biaxial compressive strain in graphene/hexagonal boron nitride heterostructures after thermal cycling to high temperatures likely due to their thermal expansion coefficient mismatch. The appearance of sub-micron self-supporting bubbles indicates that the strain is spatially inhomogeneous. Finite element modeling suggests that the strain is concentrated on the edges with regular nano-scale wrinkles, which could be a playground for strain engineering in graphene. Raman spectroscopy and mapping is employed to quantitatively probe the magnitude and distribution of strain. From the temperature-dependent shifts of Raman G and 2D peaks, we estimate the TEC of graphene from room temperature to above 1000K for the first time.
authors.affiliation: National Laboratory of Microstructures, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.forename: Jianliang
authors.initials: J
authors.lastname: Xiao
authors.forename: Junwei
authors.initials: J
authors.lastname: Zhu
authors.forename: Chenxi
authors.initials: C
authors.lastname: Yu
authors.forename: Gang
authors.initials: G
authors.lastname: Zhang
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Ni
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Taniguchi
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi
authors.forename: Xinran
authors.initials: X
authors.lastname: Wang