... different, quantum, nature may also be carried by the electron spin Many proposals for advances in information processing, the development of quantum computing and spin electronic devices, involve manipulation ... can be varied from just below 1.5 to above eV as x varies from to However, AlxGa1-xAs becomes an indirect semiconductor, where the conduction band minimum does not occur at the same wavevector ... scattering and the D’Yakonov-Perel mechanism in a high mobility electron gas 4.1 Introduction Electron spin evolution in III- V semiconductor quantum wells is governed by the D’Yakonov-Perel mechanism...
... (Table III) 19 | P a g e Table III: Available 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 ... 2.3 QuantumDotSynthesis 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 ... dyes and quantum dots Table II: Important parameters of bulk semiconductors commonly used for quantum dots 15 Table III: Available synthesis methods for producing II-VI semiconductor...
... as quantumdot molecules and ensembles, transition between single and double quantum rings, low-density QDs, and nano-scale templates have been demonstrated [15–32] In this article, we show various ... D.P DiVincenzo, Phys Rev B 59, 2070 (1999) A Imamoglu, D.D Awschalom, G Burkard, D.P DiVincenzo, D Loss, M Sherwin, A Small, Phys Rev Lett 83, 4204 (1999) X Xu, D.A Williams, J.R.A Cleaver, Appl ... substrate temperature and vice versa for a fixed amount of deposition [17–20, 27–29] One thing to notice in this set of samples is that the density of droplet was very sensitive to the temperature...
... Weimert J, Zhukov A: Quantumdot laser with 75 nm broad spectrum of emission Opt Lett 2007, 32:793-795 26 Zhukov AE, Kovsh AR: Quantumdot diode lasers for optical communication system Quantum Electron ... tunable quantumdot lasers with low injection current density Opt Express 2010, 18:8916-8922 Fedorova KA, Cataluna MA, Krestnikov I, Livshits D, Rafailov EU: Broadly tunable high-power InAs/GaAs quantum- dot ... penetration depth and improve the imaging sensitivity [30] Numerical investigation [31] and experimental evidence [32, 33] have shown that this limitation can be overcome by using a multi-section...
... Weimert J, Zhukov A: Quantumdot laser with 75 nm broad spectrum of emission Opt Lett 2007, 32:793-795 26 Zhukov AE, Kovsh AR: Quantumdot diode lasers for optical communication system Quantum Electron ... tunable quantumdot lasers with low injection current density Opt Express 2010, 18:8916-8922 Fedorova KA, Cataluna MA, Krestnikov I, Livshits D, Rafailov EU: Broadly tunable high-power InAs/GaAs quantum- dot ... penetration depth and improve the imaging sensitivity [30] Numerical investigation [31] and experimental evidence [32, 33] have shown that this limitation can be overcome by using a multi-section...
... observed UV-vis absorption spectra shown in Figure Similar results have been obtained in CdS-sensitized QDSSCs [31] Moreover, it should be noted that although the conduction band (CB) level of ... confirmed by using X-ray diffraction (XRD) (Rigaku D/MAX 2500 V diffractor; Rigaku Corporation, Tokyo, Japan) The UVvisible (UV-vis) absorbance spectroscopy was obtained from a S-4100 spectrometer ... achieved using a simple sequential chemical bath deposition (CBD) method In order to improve the efficiencies of as-prepared Ag2S quantum dot- sensitized solar cells, the Figure The photoconversion...
... levels in the quantumdot Solid and broken lines indicate G1,+ and G1,-, respectively The level broadening by the tunnel coupling to the source and drain is ΓS = ΓD1 ≡ Γ (VS,1/VS,2 = 1/2, VD1,1/VD1,2 ... quantumdot is formed by quantum point contacts on three leads Reservoir S is a source from which spin-unpolarized electrons are injected into the quantumdot The voltage is identical in reservoirs ... for the spin-filtering device shown in Fig 1(b) The conductance G± for spin sz = ±1/2 from reservoir S to D1 is shown as a function of gate voltage Vg on the quantumdot Solid and broken lines...
... chemistry thus provides an atomically smooth GaAs surface, which is a critical requirement for subsequent selective III- V growth during device fabrication In fact, preliminary III- V molecular beam ... Mingam H: Innovative materials, devices, and CMOS technologies for low-power mobile multimedia IEEE Trans Electron Devices 2008, 55:96-130 Radosavljevic M, Dewey G, Fastenau JM, Kavalieros J, Kotlyar ... CA, USA) working in the dynamic mode Si cantilevers (Veeco, Plainview, NY, USA) with a nominal radius of 10 nm were used An SEM microscope (FEI NovaNanoSEM 230, FEI Co., Hilsboro, OR, USA) was...
... effect in semiconductor quantum- dot spin valves Phys Rev B 2008, 77:081302(R) Stefański P: Tunneling magnetoresistance anomalies in a Coulomb blockaded quantumdot Phys Rev B 2009, 79:085312 28 ... quantumdot coupled to ferromagnetic leads and side-coupled to a nonmagnetic reservoir Phys Rev B 2010, 81:035331 König J, Martinek J: Interaction-Driven Spin Precession in Quantum- Dot Spin Valves ... negative bias region occurs when the dot level εd is aligned to the Fermi level of the right lead (μR = 0) Now electrons tunnel from the right lead via the dot to the left lead because μL = eV
... jm j kK T + V A + VH + VHET + V XC j′m′j kK j′m′j kK ′ vk = E v (k) jm j kK vk (1) where T is the effective kinetic energy operator including strain, V HET is the valence and conduction ... q (E F ) = ∑ q ,v ( E F ) (3) v q ,v ( E F ) = e 2 q ,v mq * eff q ,v ( E F ) (4) where eff q ,v ( E F ) = 2 ⎛ mq* ⎜ ⎜ ⎝ ⎞ ⎟ ⎟ ⎠ ∫ dk (E z F − q ,v (k z ))( q ,v (k z )) (5) BZ ... 106:053514 Novikov SV, Zainal N, Akimov AV, Staddon AV, Kent AJ, Foxon CT: Molecular beam epitaxy as a method for the growth of freestanding zinc-blende (cubic) GaN layers and substrates J Vac Sci...
... Turnstile Device Science 2000, 290:2282 Akopian N, Lindner NH, Poem E, Berlatzky Y, Avron J, Gershoni D, Gerardot BD, Petroff PM: Entangled Photon Pairs from Semiconductor Quantum Dots Phys Rev Lett ... UV-ozone cleaners are much lower In fact, such devices can easily be self-built Conclusion In conclusion we have investigated pre-structured GaAs sample surfaces for subsequent site-selective ... other areas seem very clean In addition, by controlling the surface evolution during deoxidation using RHEED, it is made sure that enough Ga is provided to completely remove the native oxide Furthermore,...
... an InAs quantumdot in the presence of terahertz driving fields Phys Rev B 2007, 75:035307 Khomitsky DV, Sherman EYa: Nonlinear spin-charge dynamics in a driven double quantumdot Phys Rev B 2009, ... nm and U0 = 10 meV The four lowest spin-degenerate energy levels are E = 3.938 meV, E = 4.030 meV, E = 9.782 meV, E4 = 11.590 meV counted from the bottom of a single quantumdot with the tunneling ... periodic in time Phys Rev 1965, 138:B979 Demikhovskii VYa, Izrailev FM, Malyshev FM: Manifestation of Arnold diffusion in quantum systems Phys Rev Lett 2002, 88:154101 Khomitsky DV, Sherman EYa: Pulse-pumped...
... spectra and current density-voltage (JV) curves of devices with as-grown QDs with (sample A) and without AlAs capping layers (sample B) (a) Photo-current spectra and (b) J -V curves Hu et al Nanoscale ... densities (Jsc), open-circuit voltages (Voc), and maximum power density (VMJM) are summarized in Table The fill factor is calculated according to the equation: FF = (V M J M ) / (VOC J SC ) Jsc for all ... layers QDs are covered by ML AlAs layers Sample B Sample C Sample D As grown As grown Annealed for Annealed for No Yes No Yes The curves of current density versus voltage (J -V) of samples A and...
... factor (FF) and conversion efficiency (g) of FTO/TiO2/CdS and FTO/Au/TiO2/CdS cells are listed in Table It can be observed that the Isc, Voc and g have increased from 5.72 mAcm-2, 0.47 V and 0.86% for ... defined as the number of Fig I -V curves of FTO/TiO2/CdS and FTO/Au/TiO2/CdS cells Table Photovoltaic parameters of FTO/TiO2/CdS and FTO/Au/ TiO2/CdS cells Electrode Voc (V) Isc (mA/cm2) FF g (%) FTO/Au/TiO2/CdS ... film The energy levels of FTO, Au, TiO2 and CdS are schematically shown in Fig 5a The conduction band of TiO2 is -4.2 eV (vs vacuum) [33] The work function of Au is around -5.1 eV [34], lower than...
... photovoltaic properties have been studied The Si QD solar cells investigated in this work have achieved an open circuit voltage of 410 mV after various processes Parameters extracted from dark I V, ... across the diode (VD) plus the voltage across the series resistance (VRs) Light I -V (a) 100 200 300 400 Current (A) -3.0E-07 -1.3E-06 as fabricated 250C N2 -2.3E-06 250C FG V ¼ VD þ VRs 350C FG ð1Þ ... the dark I V curve at the high voltage region, Rs is obtained according to the following In a general solar cell circuit model, the total voltage across the terminals (V) equals the voltage across...
... precisely Fig Voronoi tessellations of STM view field of Fig according to a (1 3)/(2 3) domains and b (2 4) domains Table Density, d, and standard deviation of Voronoi cell area, rVc of surface ... The standard deviation of Voronoi cells for each surface reconstruction domain is also listed in Table The total area of the Voronoi cells that are not touching the edge of the view field was normalized ... measured by using ImageJ software [8, 9] The center coordinates were used for the Voronoi tessellations of the STM view field (Fig 4) and the computation of the nearest neighbor distance function...
... these samples have the same position of a maximum at ~335 meV at negative bias voltages 3.2 V for B52, V for B53, and 0.8 V for B54, correspondingly The photoresponse of B54 is several times bigger ... S, Szafraniec J, Zhang W, Mi K, Movaghar B: Nanotechnology 2005, 16:219 Lim H, Movaghar B, Tsao S, et al: Phys Rev B 2006, 74:205321 Mitin VV, Pipa VI, Sergeev AV, Dutta M, Stroscio M: Infrared ... of surface quantum dots taken at ambient conditions by AFM measurements have been used to calibrate and control the quantumdot size and density A typical AFM result for InAs quantum dots grown...