Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides
<p dir="ltr">The past decade has witnessed the rapid introduction of organic-inorganic hybrid compounds in photovoltaic applications. Motivated by the strong demand for stable and nontoxic materials in this class, we report a theoretical study on the structural, elastic, electronic,...
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2020
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| author | Syam Kumar R (18597073) |
| author2 | Akinlolu Akande (8163150) Fedwa El-Mellouhi (2011099) Heesoo Park (1604989) Stefano Sanvito (1294110) |
| author2_role | author author author author |
| author_facet | Syam Kumar R (18597073) Akinlolu Akande (8163150) Fedwa El-Mellouhi (2011099) Heesoo Park (1604989) Stefano Sanvito (1294110) |
| author_role | author |
| dc.creator.none.fl_str_mv | Syam Kumar R (18597073) Akinlolu Akande (8163150) Fedwa El-Mellouhi (2011099) Heesoo Park (1604989) Stefano Sanvito (1294110) |
| dc.date.none.fl_str_mv | 2020-07-10T09:00:00Z |
| dc.identifier.none.fl_str_mv | 10.1103/physrevmaterials.4.075401 |
| dc.relation.none.fl_str_mv | https://figshare.com/articles/journal_contribution/Theoretical_investigation_of_the_structural_elastic_electronic_and_dielectric_properties_of_alkali-metal-based_bismuth_ternary_chalcogenides/25879639 |
| dc.rights.none.fl_str_mv | CC BY 4.0 info:eu-repo/semantics/openAccess |
| dc.subject.none.fl_str_mv | Engineering Electrical engineering Materials engineering Organic-inorganic hybrid compounds Photovoltaic applications Density functional theory (DFT) Semiconductor band structure Thermodynamically and mechanically stable compounds Light absorption Dielectric functions |
| dc.title.none.fl_str_mv | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides |
| dc.type.none.fl_str_mv | Text Journal contribution info:eu-repo/semantics/publishedVersion text contribution to journal |
| description | <p dir="ltr">The past decade has witnessed the rapid introduction of organic-inorganic hybrid compounds in photovoltaic applications. Motivated by the strong demand for stable and nontoxic materials in this class, we report a theoretical study on the structural, elastic, electronic, thermodynamic and dielectric properties of alkali-metal-based bismuth ternary chalcogenides. In particular, we employ state-of-the-art density functional theory to explore the potential of Bi<sub>2</sub> and Bi<sub>3</sub> (=Na, K and = O, S) as light-absorbing media. All the compounds under investigation are found to be thermodynamically and mechanically stable, with a semiconductor band structure. The Kohn-Sham band gaps range between 0.80 eV and 1.80 eV, when calculated with semilocal functionals, values that increase to 1.24–2.47 eV with hybrid ones. Although all but NaBiO<sub>2</sub> and KBiO<sub>2</sub> are indirect band-gap semiconductors, the onset of the imaginary part of their dielectric functions, the optical gap, is only marginally larger than the quasiparticle gap. This is due to the generally flat nature of both the conduction and the valence bands. We then expect these compounds to absorb light in the upper part of the visible spectrum. In all cases the valence band is dominated by O− and S- orbitals and the conduction one by Bi-, suggesting the possibility of excitons with low binding energy. The only exceptions are NaBiO<sub>2</sub> and KBiO<sub>2</sub> for which the O− states dominate the density of states at both sides of the band gap.</p><h2>Other Information</h2><p dir="ltr">Published in: Physical Review Materials<br>License: <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank">https://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1103/physrevmaterials.4.075401" target="_blank">https://dx.doi.org/10.1103/physrevmaterials.4.075401</a></p> |
| eu_rights_str_mv | openAccess |
| id | Manara2_db22bfd48f99554ef73b840d7e58da4b |
| identifier_str_mv | 10.1103/physrevmaterials.4.075401 |
| network_acronym_str | Manara2 |
| network_name_str | Manara2 |
| oai_identifier_str | oai:figshare.com:article/25879639 |
| publishDate | 2020 |
| repository.mail.fl_str_mv | |
| repository.name.fl_str_mv | |
| repository_id_str | |
| rights_invalid_str_mv | CC BY 4.0 |
| spelling | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenidesSyam Kumar R (18597073)Akinlolu Akande (8163150)Fedwa El-Mellouhi (2011099)Heesoo Park (1604989)Stefano Sanvito (1294110)EngineeringElectrical engineeringMaterials engineeringOrganic-inorganic hybrid compoundsPhotovoltaic applicationsDensity functional theory (DFT)Semiconductor band structureThermodynamically and mechanically stable compoundsLight absorptionDielectric functions<p dir="ltr">The past decade has witnessed the rapid introduction of organic-inorganic hybrid compounds in photovoltaic applications. Motivated by the strong demand for stable and nontoxic materials in this class, we report a theoretical study on the structural, elastic, electronic, thermodynamic and dielectric properties of alkali-metal-based bismuth ternary chalcogenides. In particular, we employ state-of-the-art density functional theory to explore the potential of Bi<sub>2</sub> and Bi<sub>3</sub> (=Na, K and = O, S) as light-absorbing media. All the compounds under investigation are found to be thermodynamically and mechanically stable, with a semiconductor band structure. The Kohn-Sham band gaps range between 0.80 eV and 1.80 eV, when calculated with semilocal functionals, values that increase to 1.24–2.47 eV with hybrid ones. Although all but NaBiO<sub>2</sub> and KBiO<sub>2</sub> are indirect band-gap semiconductors, the onset of the imaginary part of their dielectric functions, the optical gap, is only marginally larger than the quasiparticle gap. This is due to the generally flat nature of both the conduction and the valence bands. We then expect these compounds to absorb light in the upper part of the visible spectrum. In all cases the valence band is dominated by O− and S- orbitals and the conduction one by Bi-, suggesting the possibility of excitons with low binding energy. The only exceptions are NaBiO<sub>2</sub> and KBiO<sub>2</sub> for which the O− states dominate the density of states at both sides of the band gap.</p><h2>Other Information</h2><p dir="ltr">Published in: Physical Review Materials<br>License: <a href="https://creativecommons.org/licenses/by/4.0/" target="_blank">https://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1103/physrevmaterials.4.075401" target="_blank">https://dx.doi.org/10.1103/physrevmaterials.4.075401</a></p>2020-07-10T09:00:00ZTextJournal contributioninfo:eu-repo/semantics/publishedVersiontextcontribution to journal10.1103/physrevmaterials.4.075401https://figshare.com/articles/journal_contribution/Theoretical_investigation_of_the_structural_elastic_electronic_and_dielectric_properties_of_alkali-metal-based_bismuth_ternary_chalcogenides/25879639CC BY 4.0info:eu-repo/semantics/openAccessoai:figshare.com:article/258796392020-07-10T09:00:00Z |
| spellingShingle | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides Syam Kumar R (18597073) Engineering Electrical engineering Materials engineering Organic-inorganic hybrid compounds Photovoltaic applications Density functional theory (DFT) Semiconductor band structure Thermodynamically and mechanically stable compounds Light absorption Dielectric functions |
| status_str | publishedVersion |
| title | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides |
| title_full | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides |
| title_fullStr | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides |
| title_full_unstemmed | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides |
| title_short | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides |
| title_sort | Theoretical investigation of the structural, elastic, electronic, and dielectric properties of alkali-metal-based bismuth ternary chalcogenides |
| topic | Engineering Electrical engineering Materials engineering Organic-inorganic hybrid compounds Photovoltaic applications Density functional theory (DFT) Semiconductor band structure Thermodynamically and mechanically stable compounds Light absorption Dielectric functions |