The impact of hexagonal boron nitride encapsulation on the structural and vibrational properties of few layer black phosphorus

Abstract

The encapsulation of two-dimensional layered materials such as black phosphorus is of paramount importance for their stability in air. However, the encapsulation poses several questions, namely, how it affects, via the weak van der Waals forces, the properties of the black phosphorus and whether these properties can be tuned on demand. Prompted by these questions, we have investigated the impact of hexagonal boron nitride encapsulation on the structural and vibrational properties of few layer black phosphorus, using a first-principles method in the framework of density functional theory. We demonstrate that the encapsulation with hexagonal boron nitride imposes biaxial strain on the black phosphorus material, flattening its puckered structure, by decreasing the thickness of the layers via the increase of the puckered angle and the intra-layer P-P bonds. This work exemplifies the evolution of structural parameters in layered materials after the encapsulation process. We find that after encapsulation, phosphorene (single layer black phosphorous) contracts by 1.1% in the armchair direction and stretches by 1.3% in the zigzag direction, whereas few layer black phosphorus mainly expands by up to 3% in the armchair direction. However, these relatively small strains induced by the hexagonal BN, lead to significant changes in the vibrational properties of black phosphorus, with the redshifts of up to 10 cm${}^{-1}$ of the high frequency optical mode $A_g^1$. In general, structural changes induced by the encapsulation process open the door to substrate controlled strain engineering in two-dimensional crystals.

arXiv comment8 pages, 5 figures, 1 table

References in corpus (32)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Van der Waals heterostructures
• Phonons and related properties of extended systems from density-functional perturbation theory
• Black phosphorus field-effect transistors
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Van der Waals density functionals applied to solids
• High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus
• Substrate-induced band gap opening in epitaxial graphene
• Effective Passivation of Exfoliated Black Phosphorus Transistors against Ambient Degradation
• The Renaissance of Black Phosphorus
• Electric field effect in ultrathin black phosphorus
• Superior mechanical flexibility of phosphorene and few-layer black phosphorus
• Direct Observation of Layer-Dependent Electronic Structure in Phosphorene
• Enhanced Thermoelectric Efficiency via Orthogonal Electrical and Thermal Conductances in Phosphorene
• Anisotropic in-plane thermal conductivity observed in few-layer black phosphorus
• Plasma-assisted fabrication of monolayer phosphorene and its Raman characterization
• High quality sandwiched black phosphorus heterostructure and its quantum oscillations
• Electrical characterization of fully encapsulated ultra thin black phosphorus-based heterostructures with graphene contacts
• Quality heterostructures from two dimensional crystals unstable in air by their assembly in inert atmosphere
• First principles calculation of vibrational Raman spectra in large systems: signature of small rings in crystalline SiO2
• The Electronic Properties of Phosphorene/Graphene and Phosphorene/Hexagonal Boron Nitride Heterostructures
• Quantum Hall Effect in Ultrahigh Mobility Two-dimensional Hole Gas of Black Phosphorus
• Probing the influence of dielectric environment on excitons in monolayer WSe2: Insight from high magnetic fields
• Graphene-on-Sapphire and Graphene-on-Glass: Raman Spectroscopy Study
• Observation of Low-frequency Interlayer Breathing Modes in Few-layer Black Phosphorus
• Interlayer electronic hybridization leads to exceptional thickness-dependent vibrational properties in few-layer black phosphorus
• Lattice Vibrational Modes and Raman Scattering Spectra of Strained Phosphorene
• Large Frequency Change with Thickness in Interlayer Breathing Mode - Significant Interlayer Interactions in Few Layer Black Phosphorus
• Evaluation of van der Waals density functionals for layered materials
• Large phosphorene in-plane contraction induced by interlayer interactions in graphene-phosphorene heterostructures
• Simulated scanning tunneling microscopy images of few-layer-phosphorus capped by graphene and hexagonal boron nitride monolayers
• Observation of A${}_g^1$ Raman mode splitting in few layers black phosphorus encapsulated with hexagonal boron nitride

Cited by in corpus (5)

• Large exciton binding energies in MnPS${}_3$ as a case study of vdW layered magnet
• Supercell-core software: a useful tool to generate an optimal supercell for vertically stacked nanomaterials
• Assessment of approaches for dispersive forces employing graphone as a case study
• Substrate screening approach for quasiparticle energies of two-dimensional interfaces with lattice mismatch
• The impact of stress on the electronic structure of phosphorus allotropes stacked on hexagonal boron nitride