We report a detailed study of the strong near-field Raman scattering enhancement which takes place in tip-enhanced Raman scattering (TERS) in indium nitride. In addition to the well-known first-order optical phonons of indium nitride, near-field Raman modes, not detectable in the far-field, appear when approaching the plasmonic probe. The frequencies of these modes coincide with calculated energies of second order combinational modes consisting of optical zone center phonons and acoustic phonons at the edge of the Brillouin zone. The appearance of strong combinational modes suggests that TERS in indium nitride represents a special case of Raman scattering in which a resonance condition on the nanometer scale is achieved between the localized surface plasmons (LSPs) and surface plasmon polaritons (SPPs) of the probe with the surface charge oscillation of the material. We suggest that the surface charge accumulation (SCA) in InN, which can render the surface a degenerate semiconductor, is the dominating reason for the unusually large enhancement of the TERS signal as compared to other inorganic semiconductors. Thus, the plasmon-resonant TERS (PR-TERS) process in InN makes this technique an excellent tool for defect characterization of indium-rich semiconductor heterostructures and nanostructures with high carrier concentrations.
Real-time ESR tracking for sub-micron 3D magnetic mapping with VB- quantum sensors in hexagonal boron nitride
Universidade Federal de Pernambuco（伯南布哥联邦大学）；Instituto Federal de Educação, Ciência e Tecnologia de Pernambuco（伯南布哥联邦教育、科学与技术学院）；Escola Politécnica de Pernambuco, Universidade de Pernambuco（伯南布哥理工学院，伯南布哥大学）；Departamento de Física, Universidade Federal de Minas Gerais（米纳斯吉拉斯联邦大学物理系）；Faculty of Physics, Ludwig-Maximilians-Universität München（慕尼黑大学物理学院）
