Session 5-3

Abstract

While infrared spectroscopy, typically using a Fourier transform infrared spectrometer　(FTIR), is a powerful tool for characterizing various physical and chemical properties of samples, its spatial resolution is limited to microns due to the diffraction limit. In contrast, nano-FTIR, which combines scattering-type near-field scanning optical microscope and FTIR, offers nanoscale spatial resolution not only in the lateral direction but also in the depth direction. This is particularly suitable for characterizing two-dimensional samples. In this talk, we present our two recent examples. The first topic is the visualization of the two-dimensional electron gas (2DEG) in an AlGaN/GaN heterostructure, where the 2DEG is clearly observed in cross-sectional scanning using nano-FTIR.[1] In the second example, chemical analysis of the single-photon emitters in hBN is performed using nano-FTIR. In both cases, the nano-scale special resolution of the nano-FTIR in three dimensions is the key to obtaining results that could have been hidden in conventional FTIR.