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The electronic and optical properties of 2D hexagonal boron nitride are studied using first principle calculations. GW and BSE methods are employed in order to predict with better accuracy the excited and excitonic properties of this…

Mesoscale and Nanoscale Physics · Physics 2019-02-20 F. Ferreira , A. J. Chaves , N. M. R. Peres , R. M. Ribeiro

Boron nitride single layer belongs to the family of 2D materials whose optical properties are currently receiving considerable attention. Strong excitonic effects have already been observed in the bulk and still stronger effects are…

A new interpretation of the optical and energy-loss spectra of hexagonal boron nitride is provided based on first-principle calculations. We show that both spectra cannot be explained by independent-particle transitions but are strongly…

Materials Science · Physics 2007-05-23 Ludger Wirtz , Andrea Marini , Myrta Gruning , Angel Rubio

Hexagonal boron nitride is a wide bandgap semiconductor with a very high thermal and chemical stability often used in devices operating under extreme conditions. The growth of high-purity crystals has recently revealed the potential of this…

Materials Science · Physics 2016-05-04 G. Cassabois , P. Valvin , B. Gil

We compute and discuss the electronic band structure and excitonic dispersion of hexagonal boron nitride (hBN) in the single layer configuration and in three bulk polymorphs (usual AA' stacking, Bernal AB, and rhombohedral ABC). We focus on…

We combine electron energy-loss spectroscopy and first-principles calculations based on density-functional theory (DFT) to identify the lowest indirect exciton state in the in-plane charge response of hexagonal boron nitride (h-BN) single…

Mesoscale and Nanoscale Physics · Physics 2018-01-10 R. Schuster , C. Habenicht , M. Ahmad , M. Knupfer , B. Büchner

We show that hexagonal boron nitride (hBN), a two-dimensional insulator, when subjected to an external superlattice potential forms a new paradigm for electrostatically tunable excitons in the near- and mid-ultraviolet (UV). The imposed…

Mesoscale and Nanoscale Physics · Physics 2024-08-08 Pedro Ninhos , Christos Tserkezis , N. Asger Mortensen , Nuno M. R. Peres

In this letter we report a thorough analysis of the exciton dispersion in bulk hexagonal boron nitride. We solve the ab initio GW Bethe-Salpeter equation at finite $\mathbf{q}\parallel \Gamma K$, and we compare our results with recent…

Mesoscale and Nanoscale Physics · Physics 2018-02-22 Lorenzo Sponza , Hakim Amara , Claudio Attaccalite , François Ducastelle , Annick Loiseau

We report $ab$ $initio$ band diagram and optical absorption spectra of hexagonal boron nitride ($h$-BN), focusing on unravelling how the completeness of basis set for $GW$ calculations and how electron-phonon interactions (EPIs) impact on…

Materials Science · Physics 2020-07-22 Tong Shen , Xiao-Wei Zhang , Honghui Shang , Min-Ye Zhang , Xinqiang Wang , En-Ge Wang , Hong Jiang , Xin-Zheng Li

We present an \textit{ab initio} method to calculate phonon-assisted absorption and emission spectra in the presence of strong excitonic effects. We apply the method to bulk hexagonal BN which has an indirect band gap and is known for its…

Materials Science · Physics 2019-05-15 Fulvio Paleari , Henrique P. C. Miranda , Alejandro Molina-Sánchez , Ludger Wirtz

Being a flexible wide band gap semiconductor, hexagonal boron nitride (h-BN) has great potential for technological applications like efficient deep ultraviolet light sources, building block for two-dimensional heterostructures and room…

A quantitative analysis of the excitonic luminescence efficiency in hexagonal boron nitride (hBN) is carried out by cathodoluminescence in the ultraviolet range and compared with zinc oxide and diamond single crystals. A high quantum yield…

Low-dimensional materials differ from their bulk counterpart in many respects. In particular, the screening of the Coulomb interaction is strongly reduced, which can have important consequences such as the significant increase of exciton…

Biased bilayer graphene, with its easily tunable band gap, presents itself as the ideal system to explore the excitonic effect in graphene based systems. In this paper we study the excitonic optical response of such a system by combining a…

Mesoscale and Nanoscale Physics · Physics 2022-01-20 J. C. G. Henriques , Itai Epstein , N. M. R. Peres

Hexagonal boron nitride (hBN) has been attracting great attention because of its strong excitonic effects. Taking into account few-layer systems, we investigate theoretically the effects of the number of layers on quasiparticle energies,…

The twisted hexagonal boron nitride (hBN) bilayer has demonstrated exceptional properties, particularly the existence of electronic flat bands without needing a magic angle, suggesting strong excitonic effects. Therefore, a systematic…

Strongly Correlated Electrons · Physics 2023-08-25 Pedro Roman-Taboada , Estefania Obregon-Castillo , Andrés R. Botello-Mendez , Cecilia Noguez

The optical response functions and band structures of LiCoO$_2$ are studied at different levels of approximation, from density functional theory (DFT) in the generalized gradient approximation (GGA) to quasiparticle self-consistent QS$GW$…

The band structure of $\beta$-LiGaO$_2$ is calculated using the quasiparticle self-consistent QS$G\hat W$ method where the screened Coulomb interaction $\hat W$ is evaluated including electron-hole interaction ladder diagrams and $G$ is the…

Materials Science · Physics 2023-04-26 Niloufar Dadkhah , Walter R. L. Lambrecht , Dimitar Pashov , Mark van Schilfgaarde

Hexagonal boron nitride (hBN) is a wide band gap material with both strong excitonic light emission in the ultraviolet and strong exciton-phonon coupling. Luminescence experiments performed on the recently synthesized monolayer form (m-hBN)…

Materials Science · Physics 2023-02-28 Pierre Lechifflart , Fulvio Paleari , Davide Sangalli , Claudio Attaccalite

A theoretical study of the exciton binding energy in the two-dimensional hexagonal boron nitride monolayer is presented within the tight-binding approximation (TBA). A self-consistent equation for the interband electron-hole propagators is…

Materials Science · Physics 2018-03-28 Zoran Rukelj , Vito Despoja
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