Reliable Prediction of Electronic and Optical Properties of Layered and 2d Materials From Transferable Screened Range-Separated Hybrid Functionals
Abstract
The accurate description of electronic properties and optical absorption spectra is a longstanding challenge for density functional theory. Recently, the introduction of screened range-separated hybrid (SRSH) functionals for solid-state materials has allowed for the calculation of fundamental band gaps and optical absorption spectra that are in very good agreement with many-body perturbation theory. However, since solid-state SRSH functionals are typically tuned to reproduce the properties of bulk phases, their transferability to low-dimensional structures, which experience substantially different screening than in the bulk, remains an open question. In this project, we explore the transferability of SRSH functionals to several prototypical van der Waals materials, including transition-metal sulfides and selenides, indium selenide, black phosphorus, and hexagonal boron nitride. Considering the bulk and a monolayer of these materials as limiting cases, we show that the parameters of the SRSH functional can be determined systematically, using only the band-edge quasiparticle energies of these extremal structural phases as fitting targets. The resulting SRSH functionals can describe both electronic bandstructures and optical absorption spectra with accuracy comparable to more demanding ab initio many-body perturbation theory (GW and Bethe-Salpeter equation) approaches. Selected examples also demonstrate that the SRSH parameters, obtained from the bulk and monolayer reference structures, display good accuracy for band structures and optical spectra of bilayers, indicating a degree of transferability that is independent of the fitting procedure. Moreover, we have applied this methodology to semi-metals, specifically to graphene, proceeding with the fitting to the band gap in a k-point different from the Dirac cone. As a result of the excellent results with the (semi-empirical) fitting procedure, we have expanded our methodology to a fully non-empirical approach.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 02, 2024
- Accession Number
- AD1228658
Entities
People
- Leeor Kronik
Organizations
- Weizmann Institute of Science