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Journal ArticleDOI

High density quantum dots by direct laser fabrication

01 Jun 2016-MRS Advances (Springer International Publishing)-Vol. 1, Iss: 28, pp 2025-2030
TL;DR: In this paper, a study of direct laser fabrication that produces quantum dots with their density higher than the critical density without appearance of large clumps is presented, which suggests that high density quantum dots can be fabricated directly on semiconductor surfaces during epitaxial growth processes.
Abstract: We report a study of direct laser fabrication that produces quantum dots with their density higher than the critical density without appearance of large clumps. Atomic force microscopy is used to image GaAs(001) surfaces that are irradiated by high power laser pulses interferentially. The analysis suggests that high density quantum dots be fabricated directly on semiconductor surfaces during epitaxial growth processes.
Citations
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Journal ArticleDOI
TL;DR: In this article, the authors reported the fabrication of planar nanowires using a single exposure of interferential irradiation of high power laser pulses on the GaAs(001) surfaces.
Abstract: The authors report the fabrication of planar nanowires narrower than 30 nm and longer than a few micrometers, directly on the GaAs(001) surfaces when thermal gratings are created on the surface. The thermal grating is due to the temperature rise that is proportional to the laser intensity modulation, which is produced by interferential irradiation of high power laser pulses. The width of nanowires is much smaller than the laser wavelength as well as the interference period. The results suggest a novel fabrication method of nanowires directly by a single exposure of interferential irradiation of high power laser pulses on the GaAs(001) surfaces.

3 citations

Book ChapterDOI
01 Jan 2022
TL;DR: An overview of the types of QD embedded glass ceramics, the fabrication methods, the properties such as the unique absorption and PL, nonlinear optic property, and stability is discussed in this paper .
Abstract: Quantum dots (QDs) are nanometer-sized crystals made of metallic or mostly of semiconductor materials. QDs possess remarkably attractive optical and electrical properties due to the quantum-confinement effects. The major disadvantage with QDs is the instability, sensitivity, and cytotoxicity which can be overcome by a nanocomposite of QDs with other elements. Ceramic materials silica, titania, zirconia, alumina, and other metal oxides are routinely used in synthesis of numerous types of core/shell QDs. Specifically, QDs embedded glass-ceramics with unique properties have great potential applications in optoelectronics, photocatalysis, and sensors. Various top-down and bottom-up methods have been designed for the fabrication of these QD embedded ceramics. The most common methods used are comelting and sol–gel. This chapter presents an overview of the types of QD embedded glass ceramics, the fabrication methods, the properties such as the unique absorption and PL, nonlinear optic property, and stability. A comprehensive review of the applications of these QD embedded ceramics in light-emitting diode, sensors, and solar cells is also discussed.
References
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Book
01 Jan 1999
TL;DR: In this paper, the growth and structural characterisation of self-organized Quantum Dots are discussed. But they do not consider the model of ideal and real quantum Dots.
Abstract: Fabrication Techniques for Quantum Dots. Self-Organization Concepts on Crystal Surfaces. Growth and Structural Characterization of Self-Organized Quantum Dots. Modeling of Ideal and Real Quantum Dots. Electronic and Optical Properties. Electrical Properties. Photonic Devices. References. Index.

2,356 citations

Journal ArticleDOI
TL;DR: The intermediate band (IB) solar cell has been proposed to increase the current of solar cells while at the same time preserving the output voltage in order to produce an efficiency that ideally is above the limit established by Shockley and Queisser in 1961.
Abstract: The intermediate band (IB) solar cell has been proposed to increase the current of solar cells while at the same time preserving the output voltage in order to produce an efficiency that ideally is above the limit established by Shockley and Queisser in 1961. The concept is described and the present realizations and acquired understanding are explained. Quantum dots are used to make the cells but the efficiencies that have been achieved so far are not yet satisfactory. Possible ways to overcome the issues involved are depicted. Alternatively, and against early predictions, IB alloys have been prepared and cells that undoubtedly display the IB behavior have been fabricated, although their efficiency is still low. Full development of this concept is not trivial but it is expected that once the development of IB solar cells is fully mastered, IB solar cells should be able to operate in tandem in concentrators with very high efficiencies or as thin cells at low cost with efficiencies above the present ones.

342 citations

Book
09 Oct 2003
TL;DR: In this paper, the authors describe the energy of a strained disk with perturbed shape and its elasticity against shape perturbations, as well as the interaction between two strained disks.
Abstract: 1. Introduction.- 2. Growth and Characterization Techniques.- 3. Self-Organization Phenomena at Crystal Surfaces.- 4. Engineering of Complex Nanostructures: Working Together with Nature.- 5. Devices Based on Epitaxial Nanostructures.- 6. Conclusion.- A. Energy of a Strained Disk with Perturbed Shape.- A.1 Energy of the Disk Boundary.- A.2 Elastic Relaxation Energy of the Disk.- A.3 Evaluation of Integrals.- A.4 Stiffness of the Disk against Shape Perturbations.- B. Elastic Interaction of Two Strained Disks.- C. Stiffness of a Hexagonal Array of Interacting Strained Disks.- References.

214 citations

Journal ArticleDOI
TL;DR: In this paper, a method for the fabrication of large-area arrays of magnetic particles with 100 nm period, using achromatic interferometric lithography combined with etching, electrodeposition, or an evaporation and liftoff processes, is presented.
Abstract: A method is presented for the fabrication of large-area arrays of magnetic particles with 100 nm period, using achromatic interferometric lithography combined with etching, electrodeposition, or an evaporation and liftoff processes. These “nanomagnet” arrays have applications in patterned magnetic media, in magnetic memories, and for studies of particle interactions.

112 citations

Journal ArticleDOI
TL;DR: In this article, surface corrugations with a period of 1108 A and a depth of [inverted lazy s] 500 A have been fabricated in glass by optical interference of two 3250 A laser beams.
Abstract: Surface corrugations with a period of 1108 A and a depth of [inverted lazy s] 500 A have been fabricated in glass. These corrugations were first produced in a photoresist film on glass by the optical interference of two 3250‐A laser beams. The corrugation was transferred to the glass by ion beam etching.

90 citations