Energy dissipation in van der Waals two-dimensional devices

TL;DR

This paper reviews the microscopic mechanisms of energy dissipation in 2D materials like graphene and transition metal dichalcogenides, emphasizing how device configuration and substrate influence heat management and carrier relaxation.

Contribution

It provides a comprehensive overview of energy relaxation processes in 2D materials and explores how device design affects dissipation pathways and optoelectronic applications.

Findings

Energy dissipation mechanisms vary with substrate and device structure.

Carrier scattering dynamics in graphene heterostructures can be harnessed for optoelectronic devices.

Substrate and encapsulation influence energy relaxation and heat dissipation.

Abstract

Understanding the physics underlying energy dissipation is necessary for the effective thermal management of devices based on two-dimensional (2D) materials and requires insights into the interplay between heat generation and diffusion in such materials. We review the microscopic mechanisms that govern Joule heating and energy dissipation processes in 2D materials such as graphene, black phosphorus and semiconducting transition metal dichalcogenides. We discuss the processes through which non-equilibrium charge carriers, created either transiently through photoexcitation or at steady state by a large electric field, undergo energy relaxation with the lattice and the substrate We also discuss how these energy dissipation processes are affected by the device configuration (heterostructure, substrate material including hexagonal boron nitride, etc) as the use of different substrates, encapsulation, disorder, etc can introduce or remove scattering processes that change the energy relaxation pathways. Finally, we discuss how the unique carrier scattering dynamics in graphene-based vdW heterostructures can be exploited for optoelectronic applications in light emission and photodetection.