Anomalous tip-sample distance behavior on the tip-enhanced Raman spectroscopy of graphene in ambient conditions
Abstract
Tip-enhanced Raman spectroscopy (TERS) combines Raman spectroscopy with scanning probe microscopy to overcome the spatial resolution limitation imposed by light diffraction, offering a primary optical technique for the comprehensive study of two-dimensional (2D) materials. In this work, we investigate an anomalous decay profile of the TERS intensity of the graphene 2D band as the tip-sample separation changes, observations enabled by high TERS efficiency and accuracy in tip-approach and tip-retract procedures. The anomalous results can be properly described by the addition of an ad hoc deformation to the effective tip-sample distance, rationalized here as due to the presence of a liquid meniscus formed via capillary forces.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (8)
André G. Pereira
Departamento de Física, Universidade Federal de Minas Gerais 1 , Belo Horizonte, Minas Gerais 30123-970,
Raul Corrêa
Departamento de Física, Universidade Federal de Minas Gerais 1 , Belo Horizonte, Minas Gerais 30123-970,
Bianca Carneiro
Departamento de Física, Universidade Federal de Minas Gerais 1 , Belo Horizonte, Minas Gerais 30123-970,
Cassiano Rabelo
FabNS, Parque Tecnológico de Belo Horizonte-BHTec 2 , Belo Horizonte, MG 31310-260,
Thiago L. Vasconcelos
Instituto Nacional de Metrologia, Qualidade e Tecnologia 4 , Duque de Caxias, RJ 25250-020,
Vitor Monken
FabNS, Parque Tecnológico de Belo Horizonte-BHTec 2 , Belo Horizonte, MG 31310-260,
Luiz Gustavo Cançado
Departamento de Física, Universidade Federal de Minas Gerais 1 , Belo Horizonte, Minas Gerais 30123-970,
Ado Jorio
Departamento de Física, Universidade Federal de Minas Gerais 1 , Belo Horizonte, Minas Gerais 30123-970,