PROBING HEAT TRANSPORT IN 2D NANOSTRUCTURES USING ELECTRON BEAM TECHNIQUE

Abstract

In this thesis, a new thermal measurement technique to measure the spatially-resolved in-plane thermal conductivity of a 2D material system is explored. The approach is based on the 1D electron beam technique being extended to a 2D system through a data analysis process that involves inverse optimization. Numerical demonstration of thermal conductivity image reconstruction by inverse optimization has been presented, following by the experimental measurement on the inhomogeneous sample. To reduce the instability of the reconstructed results, the regularization method has been introduced in the inverse optimization. The reconstructed thermal conductivity image of the detected sample shows consistency with the expected distribution based on the pattern of the sample. This represents of proof-of-concept demonstration for 2D thermal conductivity mapping through the electron beam technique.