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Ghanbari A, Khordad R, Taghizadeh F, Nasirizadeh I, Edet C, Ali N. Impurity effect on thermal properties of tuned quantum dot/ring systems. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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Sasi S, Sugunan SK, Radhakrishnan Nair P, Subramanian KRV, Mathew S. Scope of surface-modified molecular and nanomaterials in gel/liquid forms for developing mechanically flexible DSSCs/QDSSCs. Photochem Photobiol Sci 2018; 18:15-29. [PMID: 30398278 DOI: 10.1039/c8pp00293b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The advanced lifestyle of the human race involves heavy usage of various gadgets which require copious supplies of energy for uninterrupted functioning. Due to the ongoing depletion of fossil fuels and the accelerating demand for other energy resources, renewable energy sources, especially solar cells, are being extensively explored as viable alternatives. Flexible solar cells have recently emerged as an advanced member of the photovoltaic family; the flexibility and pliability of these photovoltaic materials are advantageous from a practical point of view. Conventional flexible solar cell materials, when dispersed in solvents, are usually volatile and create severe stability issues when incorporated in devices. Recently, non-volatile, less viscous functional molecular liquids/gels have been proposed as potential materials for use in foldable device applications. This perspective article discusses the scope of surface-modified non-volatile molecular and nanomaterials in liquid/gel forms in the manufacturing and deployment of flexible photovoltaics.
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Affiliation(s)
- Soorya Sasi
- Advanced Molecular Materials Research Centre, Mahatma Gandhi University, Kottayam, Kerala, India.
| | - Sunish K Sugunan
- Advanced Molecular Materials Research Centre, Mahatma Gandhi University, Kottayam, Kerala, India. and Department of Chemistry, CMS College (Autonomous) - affiliated to Mahatma Gandhi University, Kottayam, Kerala, India
| | - P Radhakrishnan Nair
- Advanced Molecular Materials Research Centre, Mahatma Gandhi University, Kottayam, Kerala, India.
| | - K R V Subramanian
- Department of Mechanical Engineering, GITAM University, Nagadenahalli, Dodballapur Taluk, Bengaluru 562103, India
| | - Suresh Mathew
- Advanced Molecular Materials Research Centre, Mahatma Gandhi University, Kottayam, Kerala, India. and School of Chemical Sciences, Mahatma Gandhi University, Priyadarshini Hills, Kottayam, Kerala, India
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3
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Haller A, Bande A. Favoritism of quantum dot inter-Coulombic decay over direct and multi-photon ionization by laser strength and focus. J Chem Phys 2018; 149:134102. [PMID: 30292222 DOI: 10.1063/1.5042208] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Anika Haller
- Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
| | - Annika Bande
- Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin, Germany
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Bachau H, Nikolopoulos LAA. Direct and Sequential Two-Photon Double Ionization of Two-Electron Quantum Dots. J Phys Chem A 2018; 122:1574-1583. [PMID: 29356525 DOI: 10.1021/acs.jpca.7b11811] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work we study the double ionization yields and kinetic energy spectra of a two-electron spherical quantum dot (QD) exposed in laser fields. The theoretical description is based on an ab initio nonperturbative configuration interaction theory capable of describing the two-electron QD dynamics in THz and mid-IR ultrashort laser fields. The QD's confinement potential is approximated to have a Gaussian-like spatial dependence. We have found that significant variations of the two-electron kinetic energy patterns and two-photon double ionization yields occur as we vary the QD's size. For a given laser pulse, the double ionization yield increases by orders of magnitude when the dot size is reduced. The size of the QD determines the sequential or direct character of the two-photon double ionization process. Provided that it is energetically allowed, the sequential two-photon double ionization process, requiring minimal interelectronic correlations, becomes dominant over the direct one. In the sequential regime, the corresponding two-electron kinetic energy spectrum changes from a broadened single-peaked to a doubly peaked one. Moreover, we also have identified features in the spectrum that are distinctively different than those in its atomic counterpart.
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Affiliation(s)
- Henri Bachau
- Centre des Lasers Intenses et Applications, Université de Bordeaux-CNRS-CEA , F-33405 Talence Cedex, France
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Konishi T, Clarke E, Burrows CW, Bomphrey JJ, Murray R, Bell GR. Spatial regularity of InAs-GaAs quantum dots: quantifying the dependence of lateral ordering on growth rate. Sci Rep 2017; 7:42606. [PMID: 28211899 PMCID: PMC5304192 DOI: 10.1038/srep42606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/11/2017] [Indexed: 11/21/2022] Open
Abstract
The lateral ordering of arrays of self-assembled InAs-GaAs quantum dots (QDs) has been quantified as a function of growth rate, using the Hopkins-Skellam index (HSI). Coherent QD arrays have a spatial distribution which is neither random nor ordered, but intermediate. The lateral ordering improves as the growth rate is increased and can be explained by more spatially regular nucleation as the QD density increases. By contrast, large and irregular 3D islands are distributed randomly on the surface. This is consistent with a random selection of the mature QDs relaxing by dislocation nucleation at a later stage in the growth, independently of each QD’s surroundings. In addition we explore the statistical variability of the HSI as a function of the number N of spatial points analysed, and we recommend N > 103 to reliably distinguish random from ordered arrays.
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Affiliation(s)
- T Konishi
- Centre for Collaborative Research, National Institute of Technology, Anan College, Anan, Tokushima, Japan
| | - E Clarke
- EPSRC National Centre for III-V Technologies, Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom
| | - C W Burrows
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - J J Bomphrey
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - R Murray
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ, United Kingdom
| | - G R Bell
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
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6
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Lim EK, Kim T, Paik S, Haam S, Huh YM, Lee K. Nanomaterials for Theranostics: Recent Advances and Future Challenges. Chem Rev 2014; 115:327-94. [DOI: 10.1021/cr300213b] [Citation(s) in RCA: 916] [Impact Index Per Article: 91.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Eun-Kyung Lim
- Department
of Radiology, Yonsei University, Seoul 120-752, Korea
- BioNanotechnology
Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Korea
| | - Taekhoon Kim
- Department
of Chemistry, Korea University, Seoul 136-701, Korea
- Electronic
Materials Laboratory, Samsung Advanced Institute of Technology, Mt. 14-1,
Nongseo-Ri, Giheung-Eup, Yongin-Si, Gyeonggi-Do 449-712, Korea
| | - Soonmyung Paik
- Severance
Biomedical Research Institute, Yonsei University College of Medicine, Seoul 120-749, Korea
- Division
of Pathology, NSABP Foundation, Pittsburgh, Pennsylvania 15212, United States
| | - Seungjoo Haam
- Department
of Chemical and Biomolecular Engineering, Yonsei University, Seoul 120-749, Korea
| | - Yong-Min Huh
- Department
of Radiology, Yonsei University, Seoul 120-752, Korea
| | - Kwangyeol Lee
- Department
of Chemistry, Korea University, Seoul 136-701, Korea
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7
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Warburton RJ. Single spins in self-assembled quantum dots. NATURE MATERIALS 2013; 12:483-93. [PMID: 23695745 DOI: 10.1038/nmat3585] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 01/29/2013] [Indexed: 05/22/2023]
Abstract
Self-assembled quantum dots have excellent photonic properties. For instance, a single quantum dot is a high-brightness, narrow-linewidth source of single photons. Furthermore, the environment of a single quantum dot can be tailored relatively easily using semiconductor heterostructure and post-growth processing techniques, enabling electrical control of the quantum dot charge and control over the photonic modes with which the quantum dot interacts. A single electron or hole trapped inside a quantum dot has spintronics applications. Although the spin dephasing is rather rapid, a single spin can be manipulated using optical techniques on subnanosecond timescales. Optical experiments are also providing new insights into old issues, such as the central spin problem. This Review provides a snapshot of this active field, with some indications for the future. It covers the basic materials and optical properties of single quantum dots, techniques for initializing, manipulating and reading out single spin qubits, and the mechanisms that limit the electron-spin and hole-spin coherence.
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Schramm A, Tommila J, Strelow C, Hakkarainen TV, Tukiainen A, Dumitrescu M, Mews A, Kipp T, Guina M. Large array of single, site-controlled InAs quantum dots fabricated by UV-nanoimprint lithography and molecular beam epitaxy. NANOTECHNOLOGY 2012; 23:175701. [PMID: 22481170 DOI: 10.1088/0957-4484/23/17/175701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present the growth of single, site-controlled InAs quantum dots on GaAs templates using UV-nanoimprint lithography and molecular beam epitaxy. A large quantum dot array with a period of 1.5 µm was achieved. Single quantum dots were studied by steady-state and time-resolved micro-photoluminescence experiments. We obtained single exciton emission with a linewidth of 45 µeV. In time-resolved experiments, we observed decay times of about 670 ps. Our results underline the potential of nanoimprint lithography and molecular beam epitaxy to create large-scale, single quantum dot arrays.
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Affiliation(s)
- A Schramm
- Optoelectronics Research Centre, Tampere University of Technology, FIN-33101 Tampere, Finland.
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9
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Bande A, Gokhberg K, Cederbaum LS. Dynamics of interatomic Coulombic decay in quantum dots. J Chem Phys 2011; 135:144112. [DOI: 10.1063/1.3646205] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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On the Size of Quantum Dots with Bound Hydrogenic Impurity States. B KOREAN CHEM SOC 2009. [DOI: 10.5012/bkcs.2009.30.2.315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Lehtonen O, Sundholm D, Vänskä T. Computational studies of semiconductor quantum dots. Phys Chem Chem Phys 2008; 10:4535-50. [DOI: 10.1039/b804212h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Erni R, Browning ND. Quantification of the size-dependent energy gap of individual CdSe quantum dots by valence electron energy-loss spectroscopy. Ultramicroscopy 2007; 107:267-73. [PMID: 16996213 DOI: 10.1016/j.ultramic.2006.08.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2006] [Revised: 07/27/2006] [Accepted: 08/09/2006] [Indexed: 11/28/2022]
Abstract
Valence electron energy-loss spectroscopy (VEELS) performed in a monochromated scanning transmission electron microscope was used to measure the energy gaps of individual quantum dots (QDs). The gap energies of a series of CdSe QDs measured by VEELS reveal the expected quantum confinement effect; the gap energy increases with decreasing particle size. However, the values derived from these first VEELS measurements of single QDs are larger than the values commonly measured by optical spectroscopy. As standard optical methods lack the spatial resolution to probe individual nanoparticles, the particle-size distribution influences the optical response. It is suggested that the impact of the particle-size distribution accounts for the discrepancy between the energy-gap values derived from VEELS of single QDs and from optical methods of ensembles of QDs.
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Affiliation(s)
- Rolf Erni
- Department of Chemical Engineering and Materials Science, University of California Davis, One Shields Ave., Davis, CA 95616, USA.
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13
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Ester P, Stufler S, Michaelis de Vasconcellos S, Bichler M, Zrenner A. High resolution photocurrent-spectroscopy of a single quantum dot. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pssc.200671572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Borri P, Schneider S, Langbein W, Bimberg D. Ultrafast carrier dynamics in InGaAs quantum dot materials and devices. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/1464-4258/8/4/s03] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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15
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Duque CA, Porras-Montenegro N, Barticevic Z, Pacheco M, Oliveira LE. Effects of applied magnetic fields and hydrostatic pressure on the optical transitions in self-assembled InAs/GaAs quantum dots. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2006; 18:1877-1884. [PMID: 21697562 DOI: 10.1088/0953-8984/18/6/005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A theoretical study of the photoluminescence peak energies in InAs self-assembled quantum dots embedded in a GaAs matrix in the presence of magnetic fields applied perpendicular to the sample plane is performed. The effective mass approximation and a parabolic potential cylinder-shaped model for the InAs quantum dots are used to describe the effects of magnetic field and hydrostatic pressure on the correlated electron-hole transition energies. Theoretical results are found in quite good agreement with available experimental measurements for InAs/GaAs self-assembled quantum dots.
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Affiliation(s)
- C A Duque
- Instituto de Física, Universidad de Antioquia, AA 1226, Medellín, Colombia
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Stufler S, Ester P, Zrenner A, Bichler M. Ramsey fringes in an electric-field-tunable quantum dot system. PHYSICAL REVIEW LETTERS 2006; 96:037402. [PMID: 16486766 DOI: 10.1103/physrevlett.96.037402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Indexed: 05/06/2023]
Abstract
We report on Ramsey fringes measured in a single InGaAs/GaAs quantum dot two-level system. We are able to control the transition energy of the system by Stark effect tuning. In combination with double pulse excitation this allows for a voltage controlled preparation of the phase and the occupancy of the two-level system. For long pulse delay times we observe extremely narrow fringes with spectral width below the homogeneous linewidth of the system. Implications on quantum information processing are discussed.
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Affiliation(s)
- S Stufler
- Universität Paderborn, Warburger Strasse 100, D-33098 Paderborn, Germany.
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Prudente FV, Costa LS, Vianna JDM. A study of two-electron quantum dot spectrum using discrete variable representation method. J Chem Phys 2005; 123:224701. [PMID: 16375489 DOI: 10.1063/1.2131068] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A variational method called discrete variable representation is applied to study the energy spectra of two interacting electrons in a quantum dot with a three-dimensional anisotropic harmonic confinement potential. This method, applied originally to problems in molecular physics and theoretical chemistry, is here used to solve the eigenvalue equation to relative motion between the electrons. The two-electron quantum dot spectrum is determined then with a precision of at least six digits. Moreover, the electron correlation energies for various potential confinement parameters are investigated for singlet and triplet states. When possible, the present results are compared with the available theoretical values.
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Affiliation(s)
- Frederico V Prudente
- Instituto de Física, Universidade Federal da Bahia, 40210-340 Salvador-Bahia, Brazil.
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18
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Chauvin N, Salem B, Bru-Chevallier C, Benyattou T, Guillot G, Bremond G, Monat C, Rojo-Romeo P, Gendry M. Micro-photoluminescence study of single self-organized InAs/InP quantum sticks. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2005. [DOI: 10.1016/j.msec.2005.06.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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19
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Gonzalez JI, Lee TH, Barnes MD, Antoku Y, Dickson RM. Quantum mechanical single-gold-nanocluster electroluminescent light source at room temperature. PHYSICAL REVIEW LETTERS 2004; 93:147402. [PMID: 15524840 DOI: 10.1103/physrevlett.93.147402] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2004] [Indexed: 05/24/2023]
Abstract
Electrically contacted gold-nanocluster arrays formed within electromigration-induced break junctions exhibit bright, field-dependent electroluminescence in the near infrared (650-800 nm). Intensity autocorrelation of spatially isolated individual nanocluster emission driven at high electrical frequency (f(ac)= approximately 200 MHz) reveals antibunched electroluminescence at room temperature. These results demonstrate the single quantum nature of several-atom gold molecules and suggest their use as room-temperature electrically driven single-photon sources.
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Affiliation(s)
- Jose I Gonzalez
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
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Beham E, Betz M, Trumm S, Kroutvar M, Ducommun Y, Krenner HJ, Bichler M, Leitenstorfer A, Finley JJ, Zrenner A, Abstreiter G. Physics and applications of self-assembled quantum dots. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/pssc.200404764] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Rastelli A, Stufler S, Schliwa A, Songmuang R, Manzano C, Costantini G, Kern K, Zrenner A, Bimberg D, Schmidt OG. Hierarchical self-assembly of GaAs/AlGaAs quantum dots. PHYSICAL REVIEW LETTERS 2004; 92:166104. [PMID: 15169246 DOI: 10.1103/physrevlett.92.166104] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Indexed: 05/24/2023]
Abstract
A novel structure containing self-assembled, unstrained GaAs quantum dots is obtained by combining solid-source molecular beam epitaxy and atomic-layer precise in situ etching. Photo-luminescence (PL) spectroscopy reveals light emission with very narrow inhomogeneous broadening and clearly resolved excited states at high excitation intensity. The dot morphology is determined by scanning probe microscopy and, combined with single band and eight-band k.p theory calculations, is used to interpret PL and single-dot spectra with no adjustable structural parameter.
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Affiliation(s)
- A Rastelli
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
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Urbaszek B, Warburton RJ, Karrai K, Gerardot BD, Petroff PM, Garcia JM. Fine structure of highly charged excitons in semiconductor quantum dots. PHYSICAL REVIEW LETTERS 2003; 90:247403. [PMID: 12857227 DOI: 10.1103/physrevlett.90.247403] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2002] [Indexed: 05/24/2023]
Abstract
An exciton in a symmetric semiconductor quantum dot has two possible states, one dark and one bright, split in energy by the electron-hole exchange interaction. We demonstrate that for a doubly charged exciton, there are also two states split by the electron-hole exchange, but both states are now bright. We also uncover a fine structure in the emission from the triply charged exciton. By measuring these splittings, and also those from the singly charged and doubly charged biexcitons, all on the same quantum dot, we show how the various electron-hole exchange energies can be measured without having to break the symmetry of the dot.
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Affiliation(s)
- B Urbaszek
- Department of Physics, Heriot Watt University, Edinburgh EH14 4AS, United Kingdom
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Kiraz A, Reese C, Gayral B, Zhang L, Schoenfeld WV, Gerardot BD, Petroff PM, Hu EL, Imamoglu A. Cavity-quantum electrodynamics with quantum dots. ACTA ACUST UNITED AC 2003. [DOI: 10.1088/1464-4266/5/2/303] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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