Optoelectronic Properties and Excitons in Hybridized Boron Nitride and Graphene Hexagonal Monolayers

Abstract

We explain the nature of the electronic band gap and optical absorption spectrum of Carbon - Boron Nitride (CBN) hybridized monolayers using density functional theory (DFT), GW and Bethe-Salpeter equation calculations. The CBN optoelectronic properties result from the overall monolayer bandstructure, whose quasiparticle states are controlled by the C domain size and lie at separate energy for C and BN without significant mixing at the band edge, as confirmed by the presence of strongly bound bright exciton states localized within the C domains. The resulting absorption spectra show two marked peaks whose energy and relative intensity vary with composition in agreement with the experiment, with large compensating quasiparticle and excitonic corrections compared to DFT calculations. The band gap and the optical absorption are not regulated by the monolayer composition as customary for bulk semiconductor alloys and cannot be understood as a superposition of the properties of bulk-like C and BN domains as recent experiments suggested.

References in corpus (5)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Graphene: Status and Prospects
• Energy Gaps in Graphene Nanoribbons
• Yambo: an \textit{ab initio} tool for excited state calculations
• Graphene quantum dots embedded in hexagonal boron nitride sheets

Cited by in corpus (15)

• Quasiparticle band structures and optical properties of strained monolayer MoS2 and WS2
• The GW compendium: A practical guide to theoretical photoemission spectroscopy
• First-principles study of the electrical and lattice thermal transport in monolayer and bilayer graphene
• Suppression of coherent thermal transport in quasiperiodic graphene-hBN superlattice ribbons
• One-dimensional half-metallic interfaces of two-dimensional honeycomb insulators
• Strain induced large enhancement of thermoelectric figure-of-merit ($ZT\sim 2$) in transition metal dichalcogenide monolayers ZrX${}_2$ (X= S, Se, Te)
• Contrasting interedge superexchange interactions of graphene nanoribbons embedded in h-BN and graphane
• Universal polarization energies for defects in monolayer, surface and bulk hexagonal boron nitride : A finite-size fragments GW approach
• Computing Optical Properties of Ultra-thin Crystals
• Enhancement of thermoelectric figure-of-merit of Graphene upon BN-doping and sample length reduction
• Electronic Structure, Phase Stability and Resistivity of Hybrid Hexagonal C${}_x$(BN)${}_{1-x}$ Two-dimensional Nanomaterial: A First-principles Study
• Optical and Electronic Properties of SiTe_x(x=1,2) from First-Principles
• g-B3N3C: a novel two-dimensional graphite-like material
• Tunable electronic properties of partially edge-hydrogenated armchair boron-nitrogen-carbon nanoribbons
• Giant Enhancement of Solid Solubility in Monolayer BNC Alloys by Selective Orbital Coupling