Michelson Postdoc Prize Lecture 1
Modelling and engineering of phonon-limited transport in 2D materials from first-principles
2D materials have raised tremendous interest in the condensed-matter community. They have shown fascinating fundamental physics, from electronic transport to topology; along with exciting technological prospects, from transistors to integrated optoelectronics. Many applications rely on the ability of a material to conduct electrons efficiently. At room temperature, the main intrinsic limiting factor is electron-phonon scattering. A deep understanding of phonon-limited transport, along with predictive first-principles models, are thus key to designing high-performance, energy-efficient devices. As fabrication and characterization techniques improve, theoretical and computational models also adapt to the physics of 2D materials. In particular, one must account for two aspects: dimensionality and field-effect doping, the latter being ubiquitous in experimental setups and devices.
In this colloquium, I will first discuss how developments in density-functional perturbation theory have revealed some of the consequences of those two aspects on the electron-phonon physics of gated 2D materials. From there, I will present how technologically relevant quantities like the electron mobility are computed using an accurate and automated implementation of the Boltzmann transport equation. Finally, I will discuss the design and engineering of novel materials, starting with a portfolio of close to 2000 2D materials found to be exfoliable from experimentally known bulk compounds.