Photoluminescent properties of the carbon-dimer defect in hexagonal boron-nitride: a many-body finite-size cluster approach

Abstract

We study the carbon dimer defect in a hexagonal boron-nitride monolayer using the GW and Bethe-Salpeter many-body perturbation theories within a finite size cluster approach. While quasiparticle energies converge very slowly with system size due to missing long-range polarization effects, optical excitations converge much faster, with a $1/R^3$ scaling law with respect to cluster average radius. We obtain a luminescence zero-phonon energy of 4.36 eV, including significant 0.13 eV zero-point vibrational energy and 0.15 eV reorganization energy contributions. Inter-layer screening decreases further the emission energy by about 0.3 eV. These results bring support to the recent identification of the substitutional carbon dimer as the likely source of the zero-phonon 4.1 eV luminescence line. Finally, the GW quasiparticle energies are extrapolated to the infinite h-BN monolayer limit, leading to a predicted defect HOMO-LUMO photoemission gap of 7.6 eV. Comparison with the optical gap yields a very large excitonic binding energy of 3 eV for the associated localized Frenkel exciton.

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References in corpus (9)

• The GW compendium: A practical guide to theoretical photoemission spectroscopy
• Defect-related photoluminescence of hexagonal boron nitride
• Defect Formation Energies without the Band-Gap Problem: Combining DFT and GW for the Silicon Self-Interstitial
• Coupling of excitons and defect states in boron-nitride nanostructures
• QUESTDB: a database of highly-accurate excitation energies for the electronic structure community
• First-principles identification of single photon emitters based on carbon clusters in hexagonal boron nitride
• Origin of the excitonic recombinations in hexagonal boron nitride by spatially resolved cathodoluminescence spectroscopy
• Cubic-scaling all-electron GW calculations with a separable density-fitting space-time approach
• First-principles Engineering of Charged Defects for Two-dimensional Quantum Technologies

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• Blue quantum emitter in hexagonal boron nitride and carbon chain tetramer: proposition of identification
• Universal polarization energies for defects in monolayer, surface and bulk hexagonal boron nitride : A finite-size fragments GW approach
• Creation and Microscopic Origins of Single-Photon Emitters in Transition Metal Dichalcogenides and Hexagonal Boron Nitride
• Carbon-based single photon emitters in hexagonal boron nitride with triplet ground state
• Manipulating the wavelength of single photons in insulating van der Waals heterostructures: theory and application to bilayer hexagonal boron nitride
• Deterministic fabrication of blue quantum emitters in hexagonal boron nitride