1
|
Madden E, Zwijnenburg MA. The effect of particle size on the optical and electronic properties of hydrogenated silicon nanoparticles. Phys Chem Chem Phys 2024; 26:11695-11707. [PMID: 38563473 DOI: 10.1039/d4cp00119b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
We use a combination of many-body perturbation theory and time-dependent density functional theory to study the optical and electronic properties of hydrogen terminated silicon nanoparticles. We predict that the lowest excited states of these silicon nanoparticles are excitonic in character and that the corresponding excitons are completely delocalised over the volume of the particle. The size of the excitons is predicted to increase proportionally with the particle size. Conversely, we predict that the fundamental gap, the optical gap, and the exciton binding energy increase with decreasing particle size. The exciton binding energy is predicted to counter-act the variation in the fundamental gap and hence to reduce the variation of the optical gap with particle size. The variation in the exciton binding energy itself is probably caused by a reduction in the dielectric screening with decreasing particle size. The intensity of the excited state corresponding to the optical gap and other low energy excitations are predicted to increase with decreasing particle size. We explain this increase in terms of the 'band structure' becoming smeared out in reciprocal space with decreasing particle size, increasing the 'overlap' between the occupied and unoccupied quasiparticle states and thus, the oscillator strength. Fourier transforms of the lowest excitons show that they inherit the periodicity of the frontier quasiparticle states. This, combined with the delocalisation of the exciton and the large exciton binding energy, means that the excitons in silicon nanoparticles combine aspects of Wannier-Mott, delocalisation and effect of periodicity of the underlying structure, and Frenkel, large exciton binding energy, excitons.
Collapse
Affiliation(s)
- Eimear Madden
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Martijn A Zwijnenburg
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
| |
Collapse
|
2
|
Hernández-Segura LI, Köster AM. Efficient implementation of time-dependent auxiliary density functional theory. J Chem Phys 2023; 158:024108. [PMID: 36641386 DOI: 10.1063/5.0135263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The random phase approximation of time-dependent auxiliary density functional theory (TDADFT) is rederived from auxiliary density perturbation theory. Our exhaustive validation of TDADFT reveals an upshift of the excitation energies by ∼0.1 eV with respect to standard time-dependent density functional theory. For the computationally efficient implementation of TDADFT, floating point operation optimized three-center electron repulsion integral recurrence relations and their double asymptotic expansions are implemented into the Davidson solver. The computational efficiency of TDADFT is benchmarked with four sets of molecules comprising alkanes, fullerenes, DNA fragments, and zeolites. The results show that TDADFT has a computational scaling between 1.3 and 1.9 with respect to the number of basis functions, which is lower than the scaling of standard time-dependent density functional theory. Due to its computational simplifications, TDADFT is particularly well suited for Born-Oppenheimer molecular dynamics simulations. As illustrative examples, we present the temperature effects on the gas-phase absorption spectra of benzene, naphthalene, and anthracene.
Collapse
Affiliation(s)
- Luis I Hernández-Segura
- Departamento de Química, Cinvestav, Avenida Instituto Politécnico Nacional 2508, A.P. 14-740, CDMX C.P. 07360, Mexico
| | - Andreas M Köster
- Departamento de Química, Cinvestav, Avenida Instituto Politécnico Nacional 2508, A.P. 14-740, CDMX C.P. 07360, Mexico
| |
Collapse
|
3
|
Grotjahn R, Kaupp M. Reliable TDDFT Protocol Based on a Local Hybrid Functional for the Prediction of Vibronic Phosphorescence Spectra Applied to Tris(2,2'-bipyridine)-Metal Complexes. J Phys Chem A 2021; 125:7099-7110. [PMID: 34370482 DOI: 10.1021/acs.jpca.1c05101] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An efficient computational protocol for the prediction of vibrationally resolved phosphorescence spectra is developed and validated for five tris(2,2'-bipyridine)-metal complexes ([M(bpy)3]n+, where M = Zn, Ru, Rh, Os, Ir). The outstanding feature of this protocol is the use of full linear-response time-dependent density functional theory (TDDFT) for the excited-state triplet calculation, i.e., the commonly seen strategies employing the Tamm-Dancoff approximation (TDA) or unrestricted density functional theory (DFT) calculations for the T1 state are not needed. This is achieved by the use of a local hybrid functional (LH12ct-SsirPW92) that features a real-space dependent admixture of exact exchange governed by a local mixing function. The excellent performance of this LH for triplet excitation energies known from previous studies transfers to a remarkable mean absolute error of 0.06 eV for the phosphorescence 0-0 energies investigated herein, while the popular B3PW91 functional gives an error of 0.27 eV in TDDFT and 0.09 eV in unrestricted DFT calculations, respectively. The advantages of the local hybrid are particularly apparent for excited states with a mixed-valence character. The influence of spin-orbit coupling was found to be significant for [Os(bpy)3]2+ red-shifting the 0-0 energy for phosphorescence by 0.17 eV, while the effect is negligible for the other complexes (<0.03 eV). The influence of the basis-set and integration-grid sizes is evaluated, and a computationally lighter protocol is validated that leads to drastic savings in computation time with negligible loss in accuracy.
Collapse
Affiliation(s)
- Robin Grotjahn
- Institut für Chemie, Theoretische Chemie/Quantenchemie, Technische Universität Berlin, Sekr. C7, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Martin Kaupp
- Institut für Chemie, Theoretische Chemie/Quantenchemie, Technische Universität Berlin, Sekr. C7, Straße des 17. Juni 135, D-10623 Berlin, Germany
| |
Collapse
|
4
|
Derbenyova NV, Burdov VA. Multi-carrier processes in halogenated Si nanocrystals. J Chem Phys 2020; 153:114304. [PMID: 32962396 DOI: 10.1063/5.0018514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We study theoretically an effect of passivation with Cl and Br on Auger recombination and multiple exciton generation in silicon nanocrystal Si317X172, with X being the passivating element. The nanocrystal electronic structure and rates of these processes are calculated using time-dependent density functional theory. Comparison with the H-passivated Si nanocrystal shows that the bromine coating, despite having less electronegativity, affects the electronic structure and transition rates more than the chlorine one due to the stronger structural perturbations caused by the greater surface atoms. Certain electron-hole asymmetry in both of the considered multi-carrier processes is revealed for the Br-coated silicon nanocrystal: the processes become faster if initiated by holes and slower (or invariable on the whole) if initiated by electrons. On the contrary, the chlorine coating weakly influences the multi-carrier processes.
Collapse
Affiliation(s)
- N V Derbenyova
- Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603950 Nizhny Novgorod, Russian Federation
| | - V A Burdov
- Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603950 Nizhny Novgorod, Russian Federation
| |
Collapse
|
5
|
Nguyen NL, Ma H, Govoni M, Gygi F, Galli G. Finite-Field Approach to Solving the Bethe-Salpeter Equation. PHYSICAL REVIEW LETTERS 2019; 122:237402. [PMID: 31298883 DOI: 10.1103/physrevlett.122.237402] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 12/13/2018] [Indexed: 05/26/2023]
Abstract
We present a method to compute optical spectra and exciton binding energies of molecules and solids based on the solution of the Bethe-Salpeter equation and the calculation of the screened Coulomb interaction in a finite field. The method does not require either the explicit evaluation of dielectric matrices or of virtual electronic states, and can be easily applied without resorting to the random phase approximation. In addition, it utilizes localized orbitals obtained from Bloch states using bisection techniques, thus greatly reducing the complexity of the calculation and enabling the efficient use of hybrid functionals to obtain single particle wave functions. We report exciton binding energies of several molecules and absorption spectra of condensed systems of unprecedented size, including water and ice samples with hundreds of atoms.
Collapse
Affiliation(s)
- Ngoc Linh Nguyen
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
| | - He Ma
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
| | - Marco Govoni
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
- Materials Science Division and Institute for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Francois Gygi
- Department of Computer Science, University of California Davis, Davis, California 95616, USA
| | - Giulia Galli
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA
- Materials Science Division and Institute for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA
| |
Collapse
|
6
|
Bayne MG, Scher JA, Ellis BH, Chakraborty A. Linked-Cluster Formulation of Electron–Hole Interaction Kernel in Real-Space Representation without Using Unoccupied States. J Chem Theory Comput 2018; 14:3656-3666. [DOI: 10.1021/acs.jctc.8b00123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael G. Bayne
- Department of Chemistry, Syracuse University, Syracuse, New York 13244 United States
| | - Jeremy A. Scher
- Department of Chemistry, Syracuse University, Syracuse, New York 13244 United States
| | - Benjamin H. Ellis
- Department of Chemistry, Syracuse University, Syracuse, New York 13244 United States
| | - Arindam Chakraborty
- Department of Chemistry, Syracuse University, Syracuse, New York 13244 United States
| |
Collapse
|
7
|
Abstract
Organic materials are promising candidates for advanced optoelectronics and are used in light-emitting diodes and photovoltaics. However, the underlying mechanisms allowing the formation of excited states responsible for device functionality, such as exciton generation and charge separation, are insufficiently understood. This is partly due to the wide range of existing crystalline polymorphs depending on sample preparation conditions. Here, we determine the linear optical response of thin-film single-crystal perylene samples of distinct polymorphs in transmission and reflection geometries. The sample quality allows for unprecedented high-resolution spectroscopy, which offers an ideal opportunity for judicious comparison between theory and experiment. Excellent agreement with first-principles calculations for the absorption based on the GW plus Bethe-Salpeter equation (GW-BSE) approach of many-body perturbation theory (MBPT) is obtained, from which a clear picture of the low-lying excitations in perylene emerges, including evidence of an exciton-polariton stopband, as well as an assessment of the commonly used Tamm-Dancoff approximation to the GW-BSE approach. Our findings on this well-controlled system can guide understanding and development of advanced molecular solids and functionalization for applications.
Collapse
|
8
|
Goldey MB, Brawand NP, Vörös M, Galli G. Charge Transport in Nanostructured Materials: Implementation and Verification of Constrained Density Functional Theory. J Chem Theory Comput 2017; 13:2581-2590. [DOI: 10.1021/acs.jctc.7b00088] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew B. Goldey
- Institute
for Molecule Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Nicholas P. Brawand
- Institute
for Molecule Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Márton Vörös
- Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Giulia Galli
- Institute
for Molecule Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Lemont, Illinois 60439, United States
| |
Collapse
|
9
|
Dixit A, Ángyán JG, Rocca D. Improving the accuracy of ground-state correlation energies within a plane-wave basis set: The electron-hole exchange kernel. J Chem Phys 2016; 145:104105. [DOI: 10.1063/1.4962352] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Anant Dixit
- Université de Lorraine, CRM2, UMR 7036, 54506 Vandoeuvre-lès-Nancy, France
| | - János G. Ángyán
- Université de Lorraine, CRM2, UMR 7036, 54506 Vandoeuvre-lès-Nancy, France
- CNRS, CRM2, UMR 7036, 54506 Vandoeuvre-lès-Nancy, France
| | - Dario Rocca
- Université de Lorraine, CRM2, UMR 7036, 54506 Vandoeuvre-lès-Nancy, France
- CNRS, CRM2, UMR 7036, 54506 Vandoeuvre-lès-Nancy, France
| |
Collapse
|
10
|
Bruneval F, Hamed SM, Neaton JB. A systematic benchmark of the ab initio Bethe-Salpeter equation approach for low-lying optical excitations of small organic molecules. J Chem Phys 2015; 142:244101. [PMID: 26133404 DOI: 10.1063/1.4922489] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The predictive power of the ab initio Bethe-Salpeter equation (BSE) approach, rigorously based on many-body Green's function theory but incorporating information from density functional theory, has already been demonstrated for the optical gaps and spectra of solid-state systems. Interest in photoactive hybrid organic/inorganic systems has recently increased and so has the use of the BSE for computing neutral excitations of organic molecules. However, no systematic benchmarks of the BSE for neutral electronic excitations of organic molecules exist. Here, we study the performance of the BSE for the 28 small molecules in Thiel's widely used time-dependent density functional theory benchmark set [Schreiber et al., J. Chem. Phys. 128, 134110 (2008)]. We observe that the BSE produces results that depend critically on the mean-field starting point employed in the perturbative approach. We find that this starting point dependence is mainly introduced through the quasiparticle energies obtained at the intermediate GW step and that with a judicious choice of starting mean-field, singlet excitation energies obtained from BSE are in excellent quantitative agreement with higher-level wavefunction methods. The quality of the triplet excitations is slightly less satisfactory.
Collapse
Affiliation(s)
- Fabien Bruneval
- CEA, DEN, Service de Recherches de Métallurgie Physique, F-91191 Gif-sur-Yvette, France
| | - Samia M Hamed
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jeffrey B Neaton
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| |
Collapse
|
11
|
Kühn M, Weigend F. One-Electron Energies from the Two-Component GW Method. J Chem Theory Comput 2015; 11:969-79. [DOI: 10.1021/ct501069b] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael Kühn
- Institut
für Physikalische Chemie, Karlsruher Institut für Technologie, Kaiserstraße 12, 76131 Karlsruhe, Germany
| | - Florian Weigend
- Institut
für Physikalische Chemie, Karlsruher Institut für Technologie, Kaiserstraße 12, 76131 Karlsruhe, Germany
- Institut
für Nanotechnologie, Karlsruher Institut für Technologie, Postfach 3640, 76021 Karlsruhe, Germany
| |
Collapse
|