self assembled quantum dot devices

... self- assembled quantum dots Phys Rev B 2000, 62:13595 Vdovin EE, Levin A, Patanè A, Eaves L, Main PC, Khanin YN, Dubrovskii YV, Henini M, Hill G: Imaging the electron wave function in self- assembled quantum ... doi:10.1186/1556-276X-6-115 Cite this article as: dos Santos et al.: Spin effects in InAs self- assembled quantum dots Nanoscale Research Letters 2011 6:115 Conclusion In conclusion, we have observed ... diodes Appl Phys Lett 2008, 92:143505 Loss D, DiVincenzo DP: Quantum computation with quantum dots Phys Rev A 1998, 57:120 Steane A: Quantum computing Rep Prog Phys 1998, 61:117 Submit your manuscript...

Ngày tải lên: 21/06/2014, 05:20

... influence of dot size on the FSS with a size-dependent dot shape A reduction in the QD asymmetry is found when the size is reduced The present LDE dots are in average larger than the DE dots We associate ... Conclusions In conclusion, we have studied a novel type of strain-free GaAs quantum dots which are fabricated by filling of selfassembled nanoholes generated by local droplet etching Using appropriate ... the dot elongation [6, 7] and atomistic anisotropy [7] Since the latter effect is expected to produce FSS values of less than 10 leV, we conclude that in our case the major contribution is the dot...

Ngày tải lên: 21/06/2014, 17:20

... modifying the dot structures by combining layers with different composition has proven to be effective for controlling the physical properties of self- assembled Ga0.7In0.3N0.006As Dots 5K Ga0.5In0.5N0.01As0.99 ... compared to the dot layer and barrier layer Its presence will modify the strain field or quantum confinement conditions of the dot layer A properly designed intermediate layer can improve the dot size ... coherent dot profile with aspect ratio of ~0.1 This is in good agreement with the AFM measurements, in terms of dot size The critical thickness is an important parameter governing the self- organized...

Ngày tải lên: 22/06/2014, 22:20

... a template for InAs QDs based on the SK growth mode That is, we have discovered a way to form self- assembled InAs QDs using GaAs ring-like nanostructures as templates Because the ring-like structures ... line profiling in Fig 2f With 2.0 ML coverage, more dots appeared along the perimeter of the ring-like nanostructures, such that there are ~13 dots per nanostructure and a density of ~7 · 109 cm–2 ... growth mode, exclusively performed by a hybrid approach of droplet homo-epitaxy and SK-based QD self- assembly, enables one to form new morphologies of QDs and single-QD structures that may find...

Ngày tải lên: 22/06/2014, 22:20

... doi:10.1186/1556-276X-6-208 Cite this article as: Yakimov et al.: Electromodulated reflectance study of self- assembled Ge/Si quantum dots Nanoscale Research Letters 2011 6:208 0.82 1.24 Peak C experiment parabolic ... applied perpendicular to quantum wells causes the shift of the electronic transition energy, the quantum- confined Stark effect (QCSE) [11] Type-I systems, wherein the narrow-gap dot material presents ... conduction band; ER: electroreflectance; MBE: molecular beam epitaxy; PL: photo-luminescence; QDs: quantum dots; WLs: wetting layers Acknowledgements The authors like to thank V.A Volodin for Raman measurements...

Ngày tải lên: 21/06/2014, 05:20

... (characterized by fluorescence spectroscopy) Keywords: quantum dots; biosensing; TiO2; template methods; nanoporous mask Background Semiconductor quantum dots [QDs] with exceptional physical and optical ... nanodots without the quantum confinement effect) Final quantum confinement of TiO2 QDs strongly depends on the anatase/rutile phase composition [9, 10] The phase development of TiO2 nanodots ... References Drummen GPC: Quantum Dots - From Synthesis to Applications in Biomedicine and Life Sciences Int J Mol Sci 2010, 11:154-163 Chen C, Peng J, Xia HS, Wu QS, Zeng LB: Quantum- dot- based immunofluorescent...

Ngày tải lên: 21/06/2014, 17:20

... heterostructures and devices This method allows to tune the structural properties over a wide range by adjusting the materials and the process parameters Self- assembled quantum dots are created by ... related to the GaAs quantum well Interestingly, a quantum well–related peak is missing or very weak for the samples containing LDE QDs Probably, the excitons from the GaAs quantum well migrate ... tomography, and wavelengthdivision multiplexing transmission [31] On the other hand, self- assembly of strain-free quantum dots with very uniform size distribution may help to overcome some limitations...

Ngày tải lên: 22/06/2014, 00:20

... fabricate lateral QD-molecules, based on the use of hierarchical self- assembly In hierarchically selfassembled structures the result of a self- assembly step is used as the starting point for the subsequent ... are shown Spatial ordering of QDs on the long-range scale: Quantum dot crystals As shown in the previous section, the positioning of self- assembled QDs can be well controlled on a short length scale ... References D Bimberg, M Grundmann, N.N Ledentsov, Quantum Dot Heterostructures (Wiley, Chichester, 1999) 123 10 Y Masumoto, T Takagahara, Semiconductor Quantum Dots: Physics, Spectroscopy and Applications...

Ngày tải lên: 22/06/2014, 22:20

... to fabricate novel semiconductor nanostructures 123 D Bimberg, M Grundmann, N.N Ledentsov, Quantum Dot Heterostructures (Wiley, Chichester, 1999) D Leonard, M Krishnamurthy, C.M Reaves, S.P DenBaars, ... bridged nanostructure is encouraged to form a QD pair as shown in Fig 4a Additional very small dots indicated by arrows in Fig 4a are often found to accompany the QD pair These are the remnants ... single QD pair formed after 45 s annealing at 590 °C At this even higher temperature, the QDs in the dot pairs are bigger and more separated The clear contour lines around each QD pair are steps on...

Ngày tải lên: 22/06/2014, 22:20

... have studied the temperature dependence of the luminescence of single unstrained self- assembled GaAs quantum dot (QD) structures Single QD spectroscopy showed that the QDs are characterized by ... Forschungsgemeinschaft (DFG) (Research group: Positioning of single nanostructures-single quantum devices) , and DFG (Quantum Optics in Semiconductor Nanostructures research group) References ´ J.M Gerard, ... In this work we study the temperature dependence of the emission of a single, hierarchically self- assembled GaAs/AlGaAs QD At room temperature we observe bright PL emission with FWHM of % 8.5...

Ngày tải lên: 22/06/2014, 22:20

... atoms are white Figure 1.13: A nanotechnology self- assembly process 14 More History Eric Drexler • Coined the term “Grey Goo”…the potential problem of self- replicating and autonomous artificial ... creation Issues in Science & Technology; Summer 2005 Vol 21, p49, 6p • Lieberman, Marya (2007) Self- assembled monolayers and multilayers of phthalocyanines University of Notre Dame: Department ... manufacturing is analogous to the way biological systems are made Figure 1.25: An example of a molecular self assembly through hydrogen bonds 21 Summary Nanotechnology is ubiquitous and pervasive It is...

Ngày tải lên: 15/03/2014, 23:51

... of the particles is fully covered with selfassembled SiNWs A careful examination of the image at still higher magni®cation (Fig 3d) shows Fig (a) Self- assembled SiNWs are grown on the surface ... tips of the SiNWs sub-branches 22 Z Zhang et al / Chemical Physics Letters 337 (2001) 18±24 the self- assembled SiNWs to have many subbranches of SiNWs grown out from their surface The sub-branches ... mushroom-shaped particles at still higher magni®cation, which shows clearly that the surface is full of self- assembled SiNWs 30±40 nm in diameter SiNWs at the top surface of the mushroom particles are smaller...

Ngày tải lên: 16/03/2014, 15:06

... same lateral size of 1.5 μm consists of self- assembled nanowire bundles, and some dispersive bundles can be observed from its bottom The spacing of each self- assembled structure is μm, and a large ... the spacing region between self- assembly units (b), clearly suggesting the existence of a small amount of Ga on the surface Fig SEM images of 2D ordered arrays self- assembled by SiOx nanowire ... interweaved network among the self- assembled structures on the substrate surface The composition analysis of the products was achieved using EDS Fig 2a shows EDX spectrum of the self- assembly of nanowire...

Ngày tải lên: 16/03/2014, 15:11

... 2b that the self- assembled nanowires formed nanowire bundles as a result of the synthesis approach using Na+ -based EDTA salt solution Alternatively, numerous nanorods were self- assembled to ... added to maintain the pH in a range of 1–1.2 The other conditions were held unchanged to prepare self- assembled nanorods that form urchin-like h-WO3 nanostructures The synthesized h-WO3 nanostructures ... nanocrystals with different morphologies Therefore, the present work investigates the synthesis of 1D self- assembled h-WO3 nanocrystals using sodium and ammonium ions based EDTA salt solutions Also, it...

Ngày tải lên: 19/03/2014, 16:48

... pH ( ex = 266 nm) quality of self- assembled ZnO 3D nanostructure were obtained at pH 10.5 This study was supported by the ERC (Center for Materials and Processes of Self- Assembly) program of MOST/KOSEF ... properties with a low defect concentration Overall, the best optical property and crystal quality of self- assembled ZnO 3D nanostructure were obtained at pH 10.5 Acknowledgments Fig Room-temperature ... competition between the values of TC (1 0), TC (1 1) and TC (0 2) Fig shows the FE-SEM images of the self- assembled ZnO 3D nanostructures, which were synthesized in an aqueous solution at various pH...

Ngày tải lên: 06/05/2014, 13:24

... synthesis methods for producing II-VI semiconductor quantum dots.10 2.4 Core-Shell Quantum Dots 2.4.1 Motivation for Core-Shell Quantum Dots Since quantum dots are only a few nanometers in diameter, ... Quantum Dots Work? 10 2.1.1 Semiconductors 10 2.1.2 Quantum Confinement 11 2.1.3 Fluorescence 13 2.2 Quantum Dot Materials 14 2.3 Quantum Dot ... Synthesis Techniques 16 2.4 Core-Shell Quantum Dots 20 2.4.1 Motivation for Core-Shell Quantum Dots 20 2.4.2 Types of Core-Shell Quantum Dots 21 2.4.3 Choosing a Shell Material...

Ngày tải lên: 15/05/2014, 10:25

... Contents of Volume 219 Self- Assembled Nanomaterials I Nanofibers Volume Editor: Shimizu, T ISBN: 978-3-540-85102-8 Self- Assembly of Supramolecular Nanofibers N Kimizuka Self- Assembled Peptide Nanofibers ... nanotube of self- assembled (b) TEM micrograph of the nanotubes of self- assembled The TEM micrographs were provided courtesy of Prof Myongsoo Lee of Yonsei University (c) but also its laterally assembled ... 29 2.1 2.2 Self- Assembled Nanotubes Block Copolymer Self- Assembly in Block-Selective Solvents Self- Assembled Block Copolymer Nanotubes...

Ngày tải lên: 04/06/2014, 15:04

... two self- assembled nanoscale films are studied with SECM The first system is a molecular self- assembled monolayer and the second a film consisting of gold nanoparticles Keywords Nanoparticles, self- assembled ... great interest for the possibility of making nanoscale devices by self- assembly techniques [2, 16–19] A well known method to form self- assembled nanoparticle structures is to cross-link nanoparticles ... electrical charges ix Introduction Self- assembly of chemical structures has attracted a great interest throughout the history of nanotechnology Good examples of self- assembled systems are biological...

Ngày tải lên: 04/06/2014, 15:05

... realization of sensors with improved resolution It has been proposed that self- assembled quantum dots [QDs] [10-12] and quantum well grown on a high-index surface are beneficial to broaden the ... J, Zhukov A: Quantum dot laser with 75 nm broad spectrum of emission Opt Lett 2007, 32:793-795 26 Zhukov AE, Kovsh AR: Quantum dot diode lasers for optical communication system Quantum Electron ... InAs/AlAs quantum dots for broadband emission J Appl Phys 2010, 108:103515 12 Wu J, Wang ZM, Dorogan VG, Li S, Mazur YI, Salamo GJ: Near infrared broadband emission of In0.35Ga0.65As quantum dots...

Ngày tải lên: 18/06/2014, 22:20

... Raman enhancement of rhodamine adsorbed on Ag nanoparticles self- assembled into nanowire-like arrays Marianthi Panagopoulou1, Nikolaos Pantiskos1, Panos Photopoulos2, ... with a line-arrangement of hot-spots due to the self- alignment of metallic nanoparticles, induced by the grating-like templates Keywords: SERS; self- aligned silver nanoparticles; R6G; Raman spectra; ... demonstrated that the Ag nanoparticles are preferentially deposited at the peaks of the lines forming self- assembled nanowires [12] Representative AFM images illustrating the nanowire formation on the...

Ngày tải lên: 18/06/2014, 22:20