All-optical technique to correlate defect structure and carrier transport in transferred graphene films

ACS Appl Mater Interfaces. 2013 Aug 14;5(15):7176-80. doi: 10.1021/am401518y. Epub 2013 Jul 25.

Abstract

Chemical vapor deposition of graphene on copper foil is an attractive method of producing large-area graphene films, but the electronic performance is limited by defects such as creases from the film transfer process, wrinkles due to the thermal expansion coefficient mismatch, and grain boundaries from the growth process. Here we present an all-optical technique to correlate defect structure with electronic properties using spatially resolved Raman spectroscopy and transient absorption microscopy. This technique is especially attractive since it does not require any lithographic steps to probe the electronic properties of the graphene film. As a first demonstration, we focus on the effects of both wrinkles and creases while averaging over many small grains. It was found that wrinkles and creases may decrease the charge carrier diffusion coefficient by over 50% due to increased defect scattering. This technique may easily be extended to large grain graphene films in order to study the effect of different types of grain boundaries.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.