Abstract

The presence of wrinkles in graphene can alter both the physical and electronic properties of graphene due to the strain induced by the wrinkles’ geometry. Depending on the application, wrinkles can either enhance or degrade the performance of graphene-based devices. Wrinkling can increase the mechanical strength of graphene which is suitable for stress-transfer applications [1]. However, wrinkles can decrease the carrier mobility in pristine graphene, making it undesirable for transistor applications [2]. Understanding the effects of wrinkles in graphene is important to effectively tailor them for their target applications. Raman spectroscopy is a valuable technique to characterize the various physical and chemical properties of graphene wrinkles due to the technique’s sensitivity to molecular vibrations. The size of graphene wrinkles ranges from the micro to the nanometer scale. Although much work has been done to study micrometer-sized wrinkles using conventional Raman spectroscopy, studies involving nanometer-sized wrinkles have been few. In this work, we probe the strain distribution and the charge doping in nanometer-sized monolayer graphene wrinkles using tip-enhanced Raman spectroscopy (TERS) in ambient conditions – a super-resolution technique that can provide both topographic and chemical information at nanometer-scale dimensions.

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