Directing energy transport at the nanoscale

Spatial direction of energy flow in 2D materials is critical for developing next-generation optoelectronic and thermoelectric applications. However, low-dimensional systems are prone to morphological disruptions which can strongly modify charge and heat transport. I investigate this interplay between intrinsic and extrinsic behavior in black phosphorus (BP) with photoemission electron microscopy (PEEM) and ultrafast transmission electron microscopy (UEM) to investigate morphological modification of the electronic structure and coherent acoustic phonon propagation with nanoscale resolution. These results demonstrate that in-plane broken symmetry can be developed as a novel handle for spatially-selective optical excitation and directional control of heat transport in 2D systems.