Excitons in InP/InAs inhomogeneous quantum dots

Assaid, E.; Feddi, E.; Khamkhami, J. El; Dujardin, F.

doi:10.1088/0953-8984/15/2/317

Cited by 9 publications

(3 citation statements)

References 26 publications

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“…Здесь γ -усредненное значение диэлектрической постоянной компонент рассматриваемой композиции [55]. Так как дырка тяжелее электрона, то потенциал (14) усредняем по электронным состояниям из (13).…”

Section: общие положения и приближенияunclassified

Оптические переходы и фотолюминесценция в цилиндрической ядро/слой/оболочка гетероструктуре beta-CdS/beta-HgS/beta-CdS

Aрутюнян¹,

Айрапетян²,

Казарян³

2020

Физика Твердого Тела

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In the effective mass approximation, within the framework of a simple two-band model, the states of charge carriers in the HgS quantizing layer of the cylindrical core/shell/shell β-CdS/β-HgS/β-CdS heterostructure are theoretically considered. The consideration was carried out for various intervals of geometric dimensions of sample, when the corresponding regimes of size quantization for charge carriers were realized in the layer. For each case, the electrostatic interaction between the electron and the hole is taken into account with its own specifics, and depending on the size of the sample, the corresponding values of the ground state energy of the pair are obtained. In each case, interband optical transitions in the sample and photoluminescence were also considered. It is shown that, in each individual case, taking into account the electrostatic interaction leads to a shift in the threshold frequency of interband absorption and luminescence to the short-wavelength region, and the frequency itself is determined by the geometric dimensions of the sample.

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Section: общие положения и приближенияunclassified

Оптические переходы и фотолюминесценция в цилиндрической ядро/слой/оболочка гетероструктуре beta-CdS/beta-HgS/beta-CdS

Aрутюнян¹,

Айрапетян²,

Казарян³

2020

Физика Твердого Тела

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“…The second possible solution of electrostatic equation ( 4) is Laplace equation (7), and it will give the IO phonon modes. For IO phonon modes, because (ω) = 0, via equation ( 17), ( 18), we have [37]…”

Section: The Io Phonon Modesmentioning

confidence: 99%

“…For example, in 1993, by using the method of wet chemical synthesis, Eychmüller et al [1] synthesized the inhomogeneous spherical quantum dot (QD) with an centric core barrier and several shell wells, which were called quantum dot quantum well (QDQW). The experimental [2,3] and theoretical works [4][5][6][7] on QDQWs reveal that, due to their inner configurations for electrons and holes, many physical properties in these systems are obviously different from those in homogeneous QDs. In 1997 and 1998, by means of reactive laser ablation, Suenaga and Zhang' group [8,9] successfully synthesized the inhomogeneous coaxial cylindrical quantum-well wires (QWW), termed quantum cables (QC).…”

Section: Introductionmentioning

confidence: 99%

Polar interface optical phonon modes and Fröhlich electron–phonon interaction Hamiltonians in wurtzite quantum well wires

Zhang

Shi

2005

Semicond. Sci. Technol.

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By using the dielectric continuum approximation, the polar optical phonon modes of coaxial cylindrical quantum cables with arbitrary layer-number were studied. In order to describe the vibrating of the longitudinal-optical (LO) phonons, a set of legitimate eigenfunctions for LO phonon modes are constructed and adopted. In order to deal with the interface optical (IO) phonon modes, the transfer matrix method is employed. The quantized LO and IO phonons fields, as well as their corresponding Fröhlich electron-phonon interaction Hamiltonians, are also derived. Numerical calculations on a fourlayer GaAs/AlxGa1−xAs QC have been performed. Results reveal that there are six branches of IO phonon modes. When the wave vector kz in the z direction and the azimuthal quantum number m are small, the dispersion frequencies of IO modes sensitively depend on kz and m, and the frequency forbidden behaviors of IO phonon modes were observed and the reason was analyzed. When kz and m are relatively large, with increasing kz and m, the frequency for each mode converges to the limit frequency value of IO mode in a single heterostructure, and the electrostatic potential distribution of each branch of IO mode tends to be more and more localized at some interface; meanwhile, the coupling between the electron-IO phonon becomes weaker and weaker. The calculation also shows that the phonon modes with higher frequencies have more significant contribution to the electron-phonon interaction. At last, it is found that kz and m have analogous influences on the frequencies and the electrostatic potentials of the IO phonons.

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Giant Pyramidal Near‐Infrared InP/ZnS Quantum Dots with Size Over 15 nm for Cell Imaging

Zhang,

Duan,

Tan

et al. 2024

Laser & Photonics Reviews

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In recent years, near‐infrared quantum dots (NIR QDs) have emerged as a promising candidate for biological imaging owing to their strong fluorescence penetrating into biological tissues and high imaging signal‐to‐noise ratio. Among various materials, InP QDs are environmentally friendly and have a relatively narrow bandgap of 1.35 eV, which provides a possibility for their emission wavelength to extend to the near‐infrared region. However, the strong reactivity of the precursor of phosphorus makes it challenging to synthesize NIR InP QDs, as it leads to rapid nucleation of the InP core. Herein, a method of epitaxial growth is reported to synthesize NIR InP QDs. Through high‐temperature nucleation and low‐temperature epitaxial growth, NIR InP QDs larger than 15 nm in size and with an emission wavelength of 807 nm are successfully synthesized. Furthermore, by removing InPOx defects on the surface of the core through HF etching, the quantum yield (QY) is increased from 6% to 12%. Ligand exchange successfully converted oil‐soluble ligands into water‐soluble ones, leading to excellent performance in cell imaging. The study provides a promising approach to the synthesis of desirable NIR InP QDs for use in biomedical imaging applications.

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Excitons in InP/InAs inhomogeneous quantum dots

Cited by 9 publications

References 26 publications

Оптические переходы и фотолюминесценция в цилиндрической ядро/слой/оболочка гетероструктуре beta-CdS/beta-HgS/beta-CdS

Оптические переходы и фотолюминесценция в цилиндрической ядро/слой/оболочка гетероструктуре beta-CdS/beta-HgS/beta-CdS

Polar interface optical phonon modes and Fröhlich electron–phonon interaction Hamiltonians in wurtzite quantum well wires

Giant Pyramidal Near‐Infrared InP/ZnS Quantum Dots with Size Over 15 nm for Cell Imaging

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