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Gagliano L, Kruijsse M, Schefold JDD, Belabbes A, Verheijen MA, Meuret S, Koelling S, Polman A, Bechstedt F, Haverkort J, Bakkers E. Efficient Green Emission from Wurtzite Al xIn 1- xP Nanowires. Nano Lett 2018; 18:3543-3549. [PMID: 29701976 PMCID: PMC6002781 DOI: 10.1021/acs.nanolett.8b00621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/18/2018] [Indexed: 06/01/2023]
Abstract
Direct band gap III-V semiconductors, emitting efficiently in the amber-green region of the visible spectrum, are still missing, causing loss in efficiency in light emitting diodes operating in this region, a phenomenon known as the "green gap". Novel geometries and crystal symmetries however show strong promise in overcoming this limit. Here we develop a novel material system, consisting of wurtzite Al xIn1- xP nanowires, which is predicted to have a direct band gap in the green region. The nanowires are grown with selective area metalorganic vapor phase epitaxy and show wurtzite crystal purity from transmission electron microscopy. We show strong light emission at room temperature between the near-infrared 875 nm (1.42 eV) and the "pure green" 555 nm (2.23 eV). We investigate the band structure of wurtzite Al xIn1- xP using time-resolved and temperature-dependent photoluminescence measurements and compare the experimental results with density functional theory simulations, obtaining excellent agreement. Our work paves the way for high-efficiency green light emitting diodes based on wurtzite III-phosphide nanowires.
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Affiliation(s)
- L. Gagliano
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - M. Kruijsse
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - J. D. D. Schefold
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - A. Belabbes
- Institut
für Festkörpertheorie und -optik, Friedrich-Schiller-Universitat, Max-Wien-Platz 1, D-07743 Jena, Germany
| | - M. A. Verheijen
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
- Philips
Innovation Laboratories Eindhoven, High Tech Campus 11, 5656AE Eindhoven, The Netherlands
| | - S. Meuret
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - S. Koelling
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - A. Polman
- Center
for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - F. Bechstedt
- Institut
für Festkörpertheorie und -optik, Friedrich-Schiller-Universitat, Max-Wien-Platz 1, D-07743 Jena, Germany
| | - J.E.M. Haverkort
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
| | - E.P.A.M. Bakkers
- Department
of Applied Physics, Eindhoven University
of Technology, 5600 MB Eindhoven, The Netherlands
- Kavli
Institute of Nanoscience, Delft University
of Technology, 2600 GA Delft, The Netherlands
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2
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Gagliano L, Belabbes A, Albani M, Assali S, Verheijen MA, Miglio L, Bechstedt F, Haverkort JEM, Bakkers EPAM. Pseudodirect to Direct Compositional Crossover in Wurtzite GaP/In xGa 1-xP Core-Shell Nanowires. Nano Lett 2016; 16:7930-7936. [PMID: 27960532 DOI: 10.1021/acs.nanolett.6b04242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Thanks to their uniqueness, nanowires allow the realization of novel semiconductor crystal structures with yet unexplored properties, which can be key to overcome current technological limits. Here we develop the growth of wurtzite GaP/InxGa1-xP core-shell nanowires with tunable indium concentration and optical emission in the visible region from 590 nm (2.1 eV) to 760 nm (1.6 eV). We demonstrate a pseudodirect (Γ8c-Γ9v) to direct (Γ7c-Γ9v) transition crossover through experimental and theoretical approach. Time resolved and temperature dependent photoluminescence measurements were used, which led to the observation of a steep change in carrier lifetime and temperature dependence by respectively one and 3 orders of magnitude in the range 0.28 ± 0.04 ≤ x ≤ 0.41 ± 0.04. Our work reveals the electronic properties of wurtzite InxGa1-xP.
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Affiliation(s)
- L Gagliano
- Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands
| | - A Belabbes
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universitat , Max-Wien-Platz 1, D-07743 Jena, Germany
| | - M Albani
- L-NESS and Department of Materials Science, University of Milano Bicocca , 20125, Milano, Italy
| | - S Assali
- Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands
| | - M A Verheijen
- Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands
- Philips Innovation Laboratories Eindhoven , High Tech Campus 11, 5656AE Eindhoven, The Netherlands
| | - L Miglio
- L-NESS and Department of Materials Science, University of Milano Bicocca , 20125, Milano, Italy
| | - F Bechstedt
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universitat , Max-Wien-Platz 1, D-07743 Jena, Germany
| | - J E M Haverkort
- Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands
| | - E P A M Bakkers
- Department of Applied Physics, Eindhoven University of Technology , 5600 MB Eindhoven, The Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology , 2600 GA Delft, The Netherlands
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3
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Belabbes A, Bihlmayer G, Bechstedt F, Blügel S, Manchon A. Hund's Rule-Driven Dzyaloshinskii-Moriya Interaction at 3d-5d Interfaces. Phys Rev Lett 2016; 117:247202. [PMID: 28009218 DOI: 10.1103/physrevlett.117.247202] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Indexed: 06/06/2023]
Abstract
Using relativistic first-principles calculations, we show that the chemical trend of the Dzyaloshinskii-Moriya interaction (DMI) in 3d-5d ultrathin films follows Hund's first rule with a tendency similar to their magnetic moments in either the unsupported 3d monolayers or 3d-5d interfaces. We demonstrate that, besides the spin-orbit coupling (SOC) effect in inversion asymmetric noncollinear magnetic systems, the driving force is the 3d orbital occupations and their spin-flip mixing processes with the spin-orbit active 5d states control directly the sign and magnitude of the DMI. The magnetic chirality changes are discussed in the light of the interplay between SOC, Hund's first rule, and the crystal-field splitting of d orbitals.
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Affiliation(s)
- A Belabbes
- King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering Division (PSE), Thuwal 23955-6900, Saudi Arabia
| | - G Bihlmayer
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany
| | - F Bechstedt
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - S Blügel
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, D-52425 Jülich, Germany
| | - A Manchon
- King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering Division (PSE), Thuwal 23955-6900, Saudi Arabia
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4
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Greil J, Assali S, Isono Y, Belabbes A, Bechstedt F, Valega Mackenzie FO, Silov AY, Bakkers EPAM, Haverkort JEM. Optical Properties of Strained Wurtzite Gallium Phosphide Nanowires. Nano Lett 2016; 16:3703-3709. [PMID: 27175743 PMCID: PMC4901362 DOI: 10.1021/acs.nanolett.6b01038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/29/2016] [Indexed: 06/01/2023]
Abstract
Wurtzite gallium phosphide (WZ GaP) has been predicted to exhibit a direct bandgap in the green spectral range. Optical transitions, however, are only weakly allowed by the symmetry of the bands. While efficient luminescence has been experimentally shown, the nature of the transitions is not yet clear. Here we apply tensile strain up to 6% and investigate the evolution of the photoluminescence (PL) spectrum of WZ GaP nanowires (NWs). The pressure and polarization dependence of the emission together with a theoretical analysis of strain effects is employed to establish the nature and symmetry of the transitions. We identify the emission lines to be related to localized states with significant admixture of Γ7c symmetry and not exclusively related to the Γ8c conduction band minimum (CBM). The results emphasize the importance of strongly bound state-related emission in the pseudodirect semiconductor WZ GaP and contribute significantly to the understanding of the optoelectronic properties of this novel material.
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Affiliation(s)
- J. Greil
- Department of Applied
Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
| | - S. Assali
- Department of Applied
Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
| | - Y. Isono
- Department
of Mechanical Engineering, Kobe University, Kobe 657-8501, Japan
| | - A. Belabbes
- Institut für Festkörpertheorie
und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
- King Abdullah University of Science & Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - F. Bechstedt
- Institut für Festkörpertheorie
und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
| | | | - A. Yu. Silov
- Department of Applied
Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
| | - E. P. A. M. Bakkers
- Department of Applied
Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
- Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands
| | - J. E. M. Haverkort
- Department of Applied
Physics, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
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Abstract
We study amorphous Ge quantum dots embedded in a crystalline Si matrix through structure modeling and simulation using ab initio density functional theory including spin-orbit interaction and quasiparticle effects. Three models are generated by replacing a spherical region within diamond Si by Ge atoms and creating a disordered bond network with appropriate density inside the Ge quantum dot. After total-energy optimisations of the atomic geometry we compute the electronic and optical properties. We find three major effects: (i) the resulting nanostructures adopt a type-I heterostructure character; (ii) the lowest optical transitions occur only within the Ge quantum dots, and do not involve or cross the Ge-Si interface. (iii) for larger amorphous Ge quantum dots, with diameters of about 2.0 and 2.7 nm, absorption peaks appear in the mid-infrared spectral region. These are promising candidates for intense luminescence at photon energies below the gap energy of bulk Ge.
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Affiliation(s)
- M Laubscher
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
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6
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Kokott S, Pflugradt P, Matthes L, Bechstedt F. Nonmetallic substrates for growth of silicene: an ab initio prediction. J Phys Condens Matter 2014; 26:185002. [PMID: 24728001 DOI: 10.1088/0953-8984/26/18/185002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
By means of first-principles calculations we predict the stability of silicene layers as buckled honeycomb lattices on Cl-passivated Si(1 1 1) and clean CaF2(1 1 1) surfaces. The van der Waals interaction between silicene and the inert substrate stabilizes the adsorbate system while not destroying the Si pz-derived linear bands forming Dirac cones at the Brillouin zone corners. Only small gaps of about 3 and 52 meV are opened.
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7
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Assali S, Zardo I, Plissard S, Kriegner D, Verheijen MA, Bauer G, Meijerink A, Belabbes A, Bechstedt F, Haverkort JEM, Bakkers EPAM. Direct band gap wurtzite gallium phosphide nanowires. Nano Lett 2013; 13:1559-63. [PMID: 23464761 PMCID: PMC3624814 DOI: 10.1021/nl304723c] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/20/2013] [Indexed: 05/27/2023]
Abstract
The main challenge for light-emitting diodes is to increase the efficiency in the green part of the spectrum. Gallium phosphide (GaP) with the normal cubic crystal structure has an indirect band gap, which severely limits the green emission efficiency. Band structure calculations have predicted a direct band gap for wurtzite GaP. Here, we report the fabrication of GaP nanowires with pure hexagonal crystal structure and demonstrate the direct nature of the band gap. We observe strong photoluminescence at a wavelength of 594 nm with short lifetime, typical for a direct band gap. Furthermore, by incorporation of aluminum or arsenic in the GaP nanowires, the emitted wavelength is tuned across an important range of the visible light spectrum (555-690 nm). This approach of crystal structure engineering enables new pathways to tailor materials properties enhancing the functionality.
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Affiliation(s)
- S. Assali
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven,
The Netherlands
| | - I. Zardo
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven,
The Netherlands
| | - S. Plissard
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven,
The Netherlands
| | - D. Kriegner
- Institute
of Semiconductor and
Solid State Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - M. A. Verheijen
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven,
The Netherlands
- Philips Innovation
Services Eindhoven, High Tech Campus 11, 5656AE Eindhoven,
The Netherlands
| | - G. Bauer
- Institute
of Semiconductor and
Solid State Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - A. Meijerink
- Debye Institute, Utrecht University, Princetonplein 1, 3500TA Utrecht,
The Netherlands
| | - A. Belabbes
- Institut
für Festkörpertheorie
und −optik, Friedrich Schiller Universität, 07743 Jena, Germany
| | - F. Bechstedt
- Institut
für Festkörpertheorie
und −optik, Friedrich Schiller Universität, 07743 Jena, Germany
| | - J. E. M. Haverkort
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven,
The Netherlands
| | - E. P. A. M. Bakkers
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven,
The Netherlands
- Kavli
Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The
Netherlands
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8
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Schrön A, Granovskij M, Bechstedt F. Influence of on-site Coulomb interaction U on properties of MnO(001)2 × 1 and NiO(001)2 × 1 surfaces. J Phys Condens Matter 2013; 25:094006. [PMID: 23400051 DOI: 10.1088/0953-8984/25/9/094006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigate the non-polar and antiferromagnetic (001) surfaces of MnO and NiO crystallizing in the antiferromagnetic type-II phase by means of spin-polarized density functional theory. Results are presented for surface energy, magnetization, and electronic structure. Besides the comparison of the two materials with differently filled minority-spin t(2g) shells we study the influence of exchange-correlation treatment within two schemes, the generalized gradient approximation GGA and the GGA + U scheme including an effective on-site d-d interaction U.
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Affiliation(s)
- A Schrön
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität and European Theoretical Spectroscopy Facility (ETSF), Max-Wien-Platz 1, D-07743 Jena, Germany.
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9
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Leitsmann R, Küwen F, Rödl C, Panse C, Bechstedt F. Influence of Strong Electron Correlation on Magnetism in Transition-Metal Doped Si Nanocrystals. J Chem Theory Comput 2010; 6:353-8. [PMID: 26617294 DOI: 10.1021/ct9003993] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We studied the influence of strong electron correlation on magnetic properties of Si nanocrystals doped with the transition metal (TM) atoms Mn and Fe. Different approaches to describe exchange and correlation (XC) effects are compared within a density-functional framework. Beside a semilocal treatment, two different methods to include the influence of electron correlation on the localized TM 3d states are studied. They are based on XC functionals with the inclusion of on-site Coulomb repulsion or short-range screened exchange. We demonstrate a strong dependence of both electronic structure and magnetization on the used XC functional. The inclusion of strong correlation drastically changes position and occupation of the TM or TM-Si-bond-derived levels as well as the total magnetic moments.
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Affiliation(s)
- R Leitsmann
- European Theoretical Spectroscopy Facility (ETSF) and Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - F Küwen
- European Theoretical Spectroscopy Facility (ETSF) and Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - C Rödl
- European Theoretical Spectroscopy Facility (ETSF) and Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - C Panse
- European Theoretical Spectroscopy Facility (ETSF) and Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - F Bechstedt
- European Theoretical Spectroscopy Facility (ETSF) and Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
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10
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Leitsmann R, Bechstedt F. Characteristic energies and shifts in optical spectra of colloidal IV-VI semiconductor nanocrystals. ACS Nano 2009; 3:3505-3512. [PMID: 19873980 DOI: 10.1021/nn900987j] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We investigate structural, electronic, and optical properties of colloidal IV-VI semiconductor quantum dots (QDs) using an ab initio pseudopotential method and a repeated supercell approximation. In particular, rhombo-cuboctahedral quantum dots consisting of PbSe, PbTe, and SnTe with a pseudohydrogen passivation shell are investigated for different QD sizes. The obtained dependence of the confinement energy on the QD size questions the use of three-dimensional spherical potential well models for small QD structures. The predicted band gaps are almost in agreement with measured values. The calculated Franck-Condon shifts vary significantly with the QD size. Only for PbSe they may explain the Stokes shift between optical absorption and emission. For the tellurides, spectral properties such as the oscillator strength are more important.
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Affiliation(s)
- R Leitsmann
- European Theoretical Spectroscopy Facility (ETSF) and Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, Jena, Germany.
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11
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Chandola S, Hinrichs K, Gensch M, Esser N, Wippermann S, Schmidt WG, Bechstedt F, Fleischer K, McGilp JF. Structure of si(111)-in nanowires determined from the midinfrared optical response. Phys Rev Lett 2009; 102:226805. [PMID: 19658889 DOI: 10.1103/physrevlett.102.226805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Indexed: 05/28/2023]
Abstract
The anisotropic optical response of Si(111)-(4x1)/(8x2)-In in the midinfrared, where ab initio studies predict significant changes in the band structure between competing models of this important quasi-1D system, has been measured using infrared spectroscopic ellipsometry (IRSE) and reflection anisotropy spectroscopy (RAS). Both IRSE and RAS of the (8x2) phase show that the anisotropic Drude tail of the (4x1) phase is replaced by two peaks at 0.50 and 0.72 eV, which appear in ab initio optical response calculations for the hexagon model of the (8x2) structure, but not the trimer model.
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Affiliation(s)
- S Chandola
- ISAS-Institute for Analytical Sciences, Department Berlin, Albert-Einstein Str. 9, 12489 Berlin, Germany
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12
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Abstract
Based on ab initio density functional theory we present electronic properties and the optical response for Si nanocrystals embedded in amorphous SiO(2) networks. Quasi-spherical dots with diameters from 0.8 to 1.6 nm are investigated. The results for Si nanocrystals embedded in SiO(2) are compared with corresponding results for hydrogenated Si nanocrystals of the same size. The calculations show the influence of the interface between nanocrystal and matrix on the electronic properties. The results are compared with recent experimental data and discussed in detail. As striking features, strong reductions of the gaps and their diameter variation are predicted due to the oxide presence. Electronic confinement mainly influences the absorption edge while at higher photon energies only broad peaks at almost fixed positions occur.
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Affiliation(s)
- K Seino
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität and European Theoretical Spectroscopy Facility (ETSF), Max-Wien-Platz 1, 07743 Jena, Germany.
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13
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Hambach R, Giorgetti C, Hiraoka N, Cai YQ, Sottile F, Marinopoulos AG, Bechstedt F, Reining L. Anomalous angular dependence of the dynamic structure factor near Bragg reflections: graphite. Phys Rev Lett 2008; 101:266406. [PMID: 19437659 DOI: 10.1103/physrevlett.101.266406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The electron energy-loss function of graphite is studied for momentum transfers q beyond the first Brillouin zone. We find that near Bragg reflections the spectra can change drastically for very small variations in q. The effect is investigated by means of first principle calculations in the random phase approximation and confirmed by inelastic x-ray scattering measurements of the dynamic structure factor S(q, omega). We demonstrate that this effect is governed by crystal local field effects and the stacking of graphite. It is traced back to a strong coupling between excitations at small and large momentum transfers.
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Affiliation(s)
- R Hambach
- Laboratoire des Solides Irradiés, Ecole Polytechnique, CEA/DSM, CNRS, 91128 Palaiseau, France
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14
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Stekolnikov AA, Bechstedt F, Wisniewski M, Schäfer J, Claessen R. Atomic nanowires on the Pt/Ge(001) surface: buried Pt-Ge versus top Pt-Pt chains. Phys Rev Lett 2008; 100:196101. [PMID: 18518463 DOI: 10.1103/physrevlett.100.196101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Indexed: 05/26/2023]
Abstract
Combining total-energy calculations, electronic-structure studies, and scanning tunneling microscopy (STM), we demonstrate that the observed one-dimensional nanowires are composed of Pt-induced Ge structures instead of Pt chains. Pt-Ge bonds are favored versus Pt-Pt ones. The novel tetramer-dimer-chain model explains STM features and the differential conductivity. The conduction path is related to the chain of alternating Pt-Ge atoms.
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Affiliation(s)
- A A Stekolnikov
- Institut für Festkörpertheorie and -Optik, Friedrich-Schiller-Universität and European Theoretical Spectroscopy Facility (ETSF), Jena, Germany
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15
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Affiliation(s)
- F. Ortmann
- European Theoretical Spectroscopy Facility (ETSF), Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
| | - K. Hannewald
- European Theoretical Spectroscopy Facility (ETSF), Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
| | - F. Bechstedt
- European Theoretical Spectroscopy Facility (ETSF), Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
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16
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Maul R, Preuss M, Ortmann F, Hannewald K, Bechstedt F. Electronic excitations of glycine, alanine, and cysteine conformers from first-principles calculations. J Phys Chem A 2007; 111:4370-7. [PMID: 17461555 DOI: 10.1021/jp068294j] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The electronic and optical properties are studied for three conformers of amino acid molecules using gradient-corrected (spin-) density functional theory within a projector-augmented wave scheme and the supercell method. We investigate single-particle excitations such as ionization energies and electron affinities as well as pair excitations. By comparing eigenvalues resulting from several local and nonlocal energy functionals, the influence of treatment of exchange and correlation is demonstrated. The excitations are described within the Delta-self-consistent field method with an occupation number constraint to obtain excitation energies and Stokes shifts. The results are used to also discuss the optical absorption properties. In contrast to the lowest single- and two-particle excitation energies, remarkable changes are found in absorption spectra in dependence on the conformation of the molecule geometry.
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Affiliation(s)
- R Maul
- Institut für Festkörpertheorie und-optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
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17
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Stekolnikov AA, Seino K, Bechstedt F, Wippermann S, Schmidt WG, Calzolari A, Nardelli MB. Hexagon versus trimer formation in in nanowires on Si(111): energetics and quantum conductance. Phys Rev Lett 2007; 98:026105. [PMID: 17358624 DOI: 10.1103/physrevlett.98.026105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Indexed: 05/14/2023]
Abstract
The structural and electronic properties of the quasi-one-dimensional In/Si(111) surface system are calculated from first principles. It is found that the symmetry lowering of the In chains is energetically favorable, provided neighboring nanowires are correlated, giving rise to a doubling of the surface unit cell both along and perpendicular to the chain direction. The recently suggested formation of hexagons within the In nanowires [C. González, F. Flores, and J. Ortega, Phys. Rev. Lett. 96, 136101 (2006)]--in clear contrast to the trimer formation proposed earlier-drastically modifies the electron transport along the In chains, in agreement with experiment.
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Affiliation(s)
- A A Stekolnikov
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
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18
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Maul R, Ortmann F, Preuss M, Hannewald K, Bechstedt F. DFT studies using supercells and projector-augmented waves for structure, energetics, and dynamics of glycine, alanine, and cysteine. J Comput Chem 2007; 28:1817-33. [PMID: 17394241 DOI: 10.1002/jcc.20683] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A large variety of gas phase conformations of the amino acids glycine, alanine, and cysteine is studied by numerically efficient semi-local gradient-corrected density functional theory calculations using a projector-augmented wave scheme and periodic boundary conditions. Equilibrium geometries, conformational energies, dipole moments, vibrational modes, and IR optical spectra are calculated from first principles. A comparison of our results with values obtained from quantum-chemistry methods with localized basis sets and nonlocal exchange-correlation functionals as well as with experimental data is made. For conformations containing strong intramolecular hydrogen bonds deviations in their energetic ordering occur, which are traced back to different treatments of spatial nonlocality in the exchange-correlation functional. However, even for these structures, the comparison of calculated and measured vibrational frequencies shows satisfying agreement.
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Affiliation(s)
- R Maul
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
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19
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Abstract
The adsorption of adenine on graphite is analyzed from first-principles calculations as a model case for the interaction between organic molecules and chemically inert surfaces. Within density-functional theory we find no chemical bonding due to ionic or covalent interactions, only a very weak attraction at distances beyond the equilibrium position due to the lowering of the kinetic energy of the valence electrons. Electron exchange and correlation effects are much more important for the stabilization of the adsystem. They are modeled by the local density or generalized gradient approximation supplemented by the London dispersion formula for the van der Waals interaction.
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Affiliation(s)
- F Ortmann
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany.
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20
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Abstract
A comprehensive density-functional theory (DFT) study of the atomic structure, electronic properties, and optical response of the Si(001) surface at the initial stages of oxidation is presented. The most favored adsorption position of a single O atom on top of the (4 x 2)-reconstructed Si(001) surface is found at the back-bond of the "down" Si dimer atom. There is no energy barrier for oxygen insertion into this bond. The ionization energy of the surface reaches a maximum when the oxidation of the second Si monolayer starts. Oxidation leads to an increase of the energy gap between occupied and empty surface states. The calculated reflectance anisotropy spectroscopy (RAS) data in comparison with experiment suggest a considerable amount of surface disorder already after oxidation of the first monolayer.
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Affiliation(s)
- F Fuchs
- Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
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21
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Abstract
The interaction between molecular amino groups and metal surfaces is analyzed from first-principles calculations using the adsorption of adenine on Cu110 as a model case. The amino group nitrogens are found to adsorb on top of the surface copper atoms. However, the bonding clearly cannot be explained in terms of covalent interactions. Instead, we find it to be largely determined by mutual polarization and Coulomb interaction between substrate and adsorbate.
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Affiliation(s)
- M Preuss
- Institut für Festkörpertheorie und-optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany.
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22
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Hahn PH, Schmidt WG, Seino K, Preuss M, Bechstedt F, Bernholc J. Optical absorption of water: coulomb effects versus hydrogen bonding. Phys Rev Lett 2005; 94:037404. [PMID: 15698323 DOI: 10.1103/physrevlett.94.037404] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2004] [Indexed: 05/24/2023]
Abstract
The optical spectrum of water is not well understood. For example, the main absorption peak shifts upwards by 1.3 eV upon condensation, which is contrary to the behavior expected from aggregation-induced broadening of molecular levels. We investigate theoretically the effects of electron-electron and electron-hole correlations, finding that condensation leads to delocalization of the exciton onto nearby hydrogen-bonded molecules. This reduces its binding energy and has a dramatic impact on the line shape. The calculated spectrum is in excellent agreement with experiment.
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Affiliation(s)
- P H Hahn
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
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23
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Bechstedt F, Furthmüller J, Ambacher O, Goldhahn R. Comment on "mie resonances, infrared emission, and the band gap of InN". Phys Rev Lett 2004; 93:269701. [PMID: 15698045 DOI: 10.1103/physrevlett.93.269701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2004] [Indexed: 05/24/2023]
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24
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Abstract
A variety of reconstruction models is studied for the Si(110)-(16 x 2) surface using first-principles calculations. Assuming appropriate rebonding of edge atoms and surface chains buckled in antiphase, we show that steps along the [112] direction yielding a trench indeed lower the surface energy. We explain the long-range surface reconstruction and develop a geometry model based on steps, adatoms, tetramers, and interstitials. The model is able to explain the stripes of paired pentagons seen obviously in empty-state scanning tunneling microscopy images.
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Affiliation(s)
- A A Stekolnikov
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, 07743 Jena, Germany
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25
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Bechstedt F, Weissker HC, Ramos LE, Furthmüller J. Electronic excitations in Si and Ge nanocrystals: Parameterfree calculations. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/pssc.200405136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Seino K, Schmidt WG, Bechstedt F. Energetics of Si(001) surfaces exposed to electric fields and charge injection. Phys Rev Lett 2004; 93:036101. [PMID: 15323837 DOI: 10.1103/physrevlett.93.036101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Indexed: 05/24/2023]
Abstract
We perform density-functional calculations on the influence of external electric fields and electrons or holes injected into surface states on the relative stability of c(4x2) and p(2x2) reconstructed Si(001) surfaces. It is shown that an electric field parallel to the [001] direction or the insertion of electrons into surface states favors the formation of p(2x2) periodicities. Our results explain recent experimental studies reporting changes of surface reconstruction of Si and Ge(001) surfaces induced by the scanning tunneling microscope and the occurrence of p(2x2) reconstructions on (001) surfaces of n-doped Si.
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Affiliation(s)
- K Seino
- Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany.
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27
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Affiliation(s)
- M. Preuss
- Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
| | - W. G. Schmidt
- Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
| | - F. Bechstedt
- Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
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28
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Preuss M, Schmidt WG, Seino K, Furthmüller J, Bechstedt F. Ground- and excited-state properties of DNA base molecules from plane-wave calculations using ultrasoft pseudopotentials. J Comput Chem 2004; 25:112-22. [PMID: 14634999 DOI: 10.1002/jcc.10372] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We present equilibrium geometries, vibrational modes, dipole moments, ionization energies, electron affinities, and optical absorption spectra of the DNA base molecules adenine, thymine, guanine, and cytosine calculated from first principles. The comparison of our results with experimental data and results obtained by using quantum chemistry methods show that in specific cases gradient-corrected density-functional theory (DFT-GGA) calculations using ultrasoft pseudopotentials and a plane-wave basis may be a numerically efficient and accurate alternative to methods employing localized orbitals for the expansion of the electron wave functions.
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Affiliation(s)
- M Preuss
- Friedrich-Schiller-Universität, Institut für Festkörpertheorie und Theoretische Optik, Max-Wien-Platz 1, 07743 Jena, Germany
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29
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Affiliation(s)
- K. Seino
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - W. G. Schmidt
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - M. Preuss
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - F. Bechstedt
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
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30
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Schmidt WG, Hahn PH, Bechstedt F, Esser N, Vogt P, Wange A, Richter W. InP(001)-(2 x 1) surface: a hydrogen stabilized structure. Phys Rev Lett 2003; 90:126101. [PMID: 12688886 DOI: 10.1103/physrevlett.90.126101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2002] [Indexed: 05/24/2023]
Abstract
The InP(001)(2 x 1) surface has been reported to consist of a semiconducting monolayer of buckled phosphorus dimers. This apparent violation of the electron counting principle was explained by effects of strong electron correlation. Combining first-principles calculations with reflectance anisotropy spectroscopy and LEED experiments, we find that the (2 x 1) reconstruction is not at all a clean surface: it is induced by hydrogen adsorbed in an alternating sequence on the buckled P dimers. Thus, the microscopic structure of the InP growth plane relevant to standard gas phase epitaxy conditions is resolved and shown to obey the electron counting rule.
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Affiliation(s)
- W G Schmidt
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany.
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31
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Weissker HC, Furthmüller J, Bechstedt F. Excitation energies and radiative lifetimes of Ge1-xSix nanocrystals: alloying versus confinement effects. Phys Rev Lett 2003; 90:085501. [PMID: 12633435 DOI: 10.1103/physrevlett.90.085501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2002] [Indexed: 05/24/2023]
Abstract
The composition dependence of the optical and structural properties of Ge1-xSix nanocrystals is investigated by means of ab initio total-energy and electronic-structure calculations. A trimodal distribution of the Ge-Ge, Ge-Si, and Si-Si bond lengths is found. The pair-excitation energies and the Stokes shift are calculated taking into account many-body and alloying effects. They show a distinct nonlinear behavior with changing composition. The radiative lifetime decreases exponentially with increasing Ge molar fraction. The theoretical results explain recent photoluminescence measurements. They show that composition and confinement effects can be discussed nearly separately.
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Affiliation(s)
- H-Ch Weissker
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
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32
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Bechstedt F, Furthmüller J, Ferhat M, Teles LK, Scolfaro LMR, Leite JR, Davydov VY, Ambacher O, Goldhahn R. Energy gap and optical properties of InxGa1xN. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/pssa.200306164] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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33
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Abstract
We calculate the surface optical properties of the passivated Si(110) surface using a real-space multigrid technique and ab initio pseudopotentials. Rather than from the usual eigenvalue representation, the macroscopic polarizability is obtained from the solution of an initial-value problem, which allows inclusion of excitonic and local-field effects in addition to the electronic self-energy in the surface calculations. It is shown that the electron-hole attraction is largely responsible for the peculiar line shape of the surface reflectance anisotropy.
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Affiliation(s)
- P H Hahn
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany
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Bechstedt F, Stekolnikov AA, Furthmüller J, Käckell P. Origin of the different reconstructions of diamond, Si, and Ge(111) surfaces. Phys Rev Lett 2001; 87:016103. [PMID: 11461479 DOI: 10.1103/physrevlett.87.016103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2001] [Indexed: 05/23/2023]
Abstract
Ab initio calculations of the 2x1, c(2x8), and 7x7 reconstructions of the diamond, Si, and Ge(111) surfaces are reported. The pi-bonded chain, adatom, and dimer-adatom-stacking fault models are studied to understand the driving forces for a certain reconstruction. The resulting energetics, geometries, and band structures are compared for the elemental semiconductors with different atomic sizes, and chemical trends are derived. We show why the lowest-energy reconstructions are different for the group-IV materials considered.
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Affiliation(s)
- F Bechstedt
- Institut für Festkörpertheorie und Theoretische Optik, Friedrich-Schiller-Universität, 07743 Jena, Germany
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37
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Hannewald K, Glutsch S, Bechstedt F. Quantum-kinetic theory of hot luminescence from pulse-excited semiconductors. Phys Rev Lett 2001; 86:2451-2454. [PMID: 11289952 DOI: 10.1103/physrevlett.86.2451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2000] [Indexed: 05/23/2023]
Abstract
A theory of time-resolved luminescence from photoexcited semiconductors is presented. It combines quantum kinetics of hot-carrier relaxation and quantum theory of spontaneous emission. Model calculations show the "transfer" of photoluminescence from the initial signal at the pump frequency via subsequent phonon replicas until the buildup of luminescence at the excitonic resonance. Time-resolved photoluminescence is predicted to be a sensitive measure of electron-LO-phonon quantum kinetics and bottleneck effects.
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Affiliation(s)
- K Hannewald
- Friedrich-Schiller-Universität Jena, Institut für Festkörpertheorie und Theoretische Optik, Max-Wien-Platz 1, D-07743 Jena, Germany
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38
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Rosam B, Meinhold D, Löser F, Lyssenko VG, Glutsch S, Bechstedt F, Rossi F, Köhler K, Leo K. Field-induced delocalization and Zener breakdown in semiconductor superlattices. Phys Rev Lett 2001; 86:1307-1310. [PMID: 11178070 DOI: 10.1103/physrevlett.86.1307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/1999] [Indexed: 05/23/2023]
Abstract
We investigate the energy spectrum and the electron dynamics of a band in a semiconductor superlattice as a function of the electric field. Linear optical spectroscopy shows that, for high fields, the well-known localization of the Bloch states is followed by a field-induced delocalization, associated with Zener breakdown. Using time-resolved measurements, we observe Bloch oscillations in a regime where they are damped by Zener breakdown.
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Affiliation(s)
- B Rosam
- Institut fur Angewandte Photophysik, Technische Universitat Dresden, 01062 Dresden, Germany
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Schmidt WG, Bechstedt F. Geometry and electronic structure of GaAs(001)(2 x 4) reconstructions. Phys Rev B Condens Matter 1996; 54:16742-16748. [PMID: 9985804 DOI: 10.1103/physrevb.54.16742] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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41
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Esser N, Shkrebtii AI, Resch-Esser U, Springer C, Richter W, Schmidt WG, Bechstedt F. Atomic Structure of the Sb-Stabilized GaAs(100)-(2 x 4) Surface. Phys Rev Lett 1996; 77:4402-4405. [PMID: 10062529 DOI: 10.1103/physrevlett.77.4402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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42
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Gavrilenko VI, Bechstedt F. Local-field and exchange-correlation effects in optical spectra of semiconductors. Phys Rev B Condens Matter 1996; 54:13416-13419. [PMID: 9985236 DOI: 10.1103/physrevb.54.13416] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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43
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Glutsch S, Chemla DS, Bechstedt F. Numerical calculation of the optical absorption in semiconductor quantum structures. Phys Rev B Condens Matter 1996; 54:11592-11601. [PMID: 9984948 DOI: 10.1103/physrevb.54.11592] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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44
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Käckell P, Furthmüller J, Bechstedt F, Kresse G, Hafner J. Characterization of carbon-carbon bonds on the SiC(001)c(2 x 2) surface. Phys Rev B Condens Matter 1996; 54:10304-10307. [PMID: 9984809 DOI: 10.1103/physrevb.54.10304] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Santos PV, Koopmans B, Esser N, Schmidt WG, Bechstedt F. Optical Properties of Ordered As Layers on InP(110) Surfaces. Phys Rev Lett 1996; 77:759-762. [PMID: 10062895 DOI: 10.1103/physrevlett.77.759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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47
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Zywietz A, Karch K, Bechstedt F. Influence of polytypism on thermal properties of silicon carbide. Phys Rev B Condens Matter 1996; 54:1791-1798. [PMID: 9986026 DOI: 10.1103/physrevb.54.1791] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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48
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Scholze A, Schmidt WG, Bechstedt F. Structure of the diamond (111) surface: Single-dangling-bond versus triple-dangling-bond face. Phys Rev B Condens Matter 1996; 53:13725-13733. [PMID: 9983124 DOI: 10.1103/physrevb.53.13725] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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49
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Karch K, Bechstedt F, Pavone P, Strauch D. Pressure-dependent properties of SiC polytypes. Phys Rev B Condens Matter 1996; 53:13400-13413. [PMID: 9983085 DOI: 10.1103/physrevb.53.13400] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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50
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Adolph B, Gavrilenko VI, Tenelsen K, Bechstedt F. Nonlocality and many-body effects in the optical properties of semiconductors. Phys Rev B Condens Matter 1996; 53:9797-9808. [PMID: 9982540 DOI: 10.1103/physrevb.53.9797] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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