Advanced interface analysis using cross-sectional transmission electron microscopy

Abstract

Transmission Electron Microscopy (TEM) has been considered as a powerful technique to investigate the structural, chemical, and electronic properties of materials. Recently, the advanced TEM equipped with a spherical aberration corrector was introduced and actively used for uncovering the atomic-scale structure and chemical composition of nano-materials with various dimensions (from 0D to 3D) in a sub-Å level. In the real optical and electronic devices, revealing the surface and interface structure found at the regions between metal and 2D material or among different 2D materials is so crucial for improving the performance of future devices. In this case, the cross-sectional TEM analysis combined well-prepared TEM samples is needed. In this presentation, I will present various cross-sectional (S)TEM works which were performed using a Cs corrected (S)TEM combined with a focused ion beam (FIB) sample preparation technique. Firstly, I will show the interface analysis which are crucial for revealing the scientific and fundamental phenomena found at the interface between metal (In/Au alloy) and 2D semiconductor (transitional metal dichalcogenide; MoS2) for the future application of electronic devices (field-effect transistors). In addition, metallic 2H phase of niobium disulfide (Nb1+XS2) with additional niobium atoms for potential hydrogen revolution reaction (HER) catalysts is clearly visualized via cross-sectional scaning TEM (STEM) images.