photoluminescence spectroscopy of single semiconductor nanoparticles

... Absorption Spectroscopy of Single Gold Nanorods 3.1 Imaging of Single Gold Nanorods 64 3.2 Scattering Spectrum of Single Gold Nanorods 67 3.3 Transient Absorption Spectrum of Single ... spectrum of a single gold nanorod in water The spectrum is fitted with Lorentz function The band width of the spectrum is 90 meV xv | P a g e     Figure 3.4: Pump-probe spectroscopy of a single ...   It is one of the first big challenges of physical and chemistry science today to synthesize the uniform and various kinds of shape of nanoparticles, especially for noble metal nanoparticles...

Ngày tải lên: 08/09/2015, 19:44

... Science Research Institute, University of Ulsan, Ulsan, 680-749, South Korea Department of Physics, University of Ulsan, Ulsan, 680-749, South Korea Department of Semiconductor Applications, Ulsan ... dependence of the FWHM of L1 emission lines for a series of Mn concentrations Figure The emission intensity of the neutral acceptor-bound exciton line L1 The emission intensity is a function of reciprocal ... point of departure The inset of Figure shows the PL spectra for CMT with different Mn mole fractions at 300 K The line shapes of the spectra taken at 300 K consist of a single band which corresponds...

Ngày tải lên: 20/06/2014, 20:20

... dependence of the plasmon absorption of colloidal gold nanoparticles J Phys Chem B 1999, 103:4212 Amendola V, Bakr OM, Stellacci F: A study of the surface plasmon resonance of silver nanoparticles ... can be interpreted in terms of the decrease of the density of excimers [40,41] The decrease of specific surface area with increasing particle sizes reduced the density of intermolecular excimers ... HT-160, and (f) HT-180 rubrene NPs Inset of Figure 1a: Schematic chemical structure of rubrene molecule Insets of Figure 1b, d, e, and f: HR-TEM images of corresponding HT rubrene NPs observed...

Ngày tải lên: 21/06/2014, 03:20

... kinetics of carrier relaxation in self-assembled QDs was investigated by taking into account the influence of the energetically nearby continuum of wetting layer states [11] The interaction of the ... to the joint nature of the valence-to-conduction density of states in QDs This paper demonstrated that by engineering the QD size and shape, modification of the joint density of the cross transitions ... GaAs buffer layer at 600°C QDs of two different sizes were formed by depositing 2.4 and 2.6 monolayers of InAs with a growth rate of 0.056 μm/h at growth temperatures of 480°C and 520°C under As2...

Ngày tải lên: 21/06/2014, 03:20

... Energy [eV] Energy [eV] Fig a Micro PL spectra of a single deep-hole QD with height of 7.6 nm taken at varied excitation power Ie b Micro PL spectra of a single shallow-hole QD at varied Ie The laser ... eV The authors explain the FSS [µeV] Single- dot Spectroscopy (b) 1.65 Fig a Symbols: excitation power dependence of the X and XX peaks of the shallow-hole QD of Fig 2a Lines: fits with slope = for ... 180 [degree] EX- EXX [meV] XX an exciton FSS of 22 leV and a bieciton splitting of 28 leV These data demonstrate the state of the art optical quality of LDE GaAs QDs being comparable to the established...

Ngày tải lên: 21/06/2014, 17:20

... Discussion FTIR Spectroscopy Figure 1a shows the variation of total reflectance with the amount of carbon precursor (SUC) of C–SiO2 samples The investigation was done with 6, 9, 11 and 12 g of SUC for ... consisted of nanocrystalline NiO The electron diffraction reveals that there exists a small amount of Ni grains with diameter of about 30 nm in some regions of the film (see Fig 4b) Raman Spectroscopy ... vibrations of Si–O–Si or Si–O–X, where X represents ethoxy groups bonded to silicon [8, 9] The shoulder at about 1,200 cm-1 is assigned to either the transverse optical mode of the out of phase mode of...

Ngày tải lên: 22/06/2014, 01:20

... the application of aggregation induced enhancement of two-photon photoluminescence of noble metal nanoparticles Firstly, two-photon excited photoluminescence and two-photon induced singlet oxygen ... exhibits LSPR of different shapes of gold nanoparticles. 11 Figure 1.2 displays the LSPR of different sizes of gold and silver nanoparticles. 12 Figure 1.1 Different shapes or sizes of Au nanocrystals: ... images of Au NPs in the (a) absence and (b) presence of 36 mM dopamine 68 Figure 3.3 TPPL spectra of Au NPs solution (a, b) upon addition of different concentration of dopamine; (c) Plot of TPPL...

Ngày tải lên: 10/09/2015, 09:02

... properties of semiconductor nanoparticles 1.2 Current progress of semiconductor nanoparticles 1.2.1 Core-shell semiconductor nanoparticles 1.2.2 Doping of semiconductor nanoparticles ... the long-wavelength tail of ZnS emission of extremely weak intensity [71] 1.2.3 Composition of semiconductor nanoparticles With the development of core-shell semiconductor nanoparticles, size tunable ... were successfully synthesized A lot of applications of semiconductor NCs require high intensity photoluminescence In order to improve the photoluminescence of semiconductor NCs, core-shell structures...

Ngày tải lên: 10/09/2015, 09:30

... from eligible trials: authors’ name, year of publication, country of origin, type of cancer, sample size, number of polymorphisms tested and results of the study Studies were divided into two ... interpretation of potential misleading sources of literature-bias The existence of such type of bias in genetic association studies might lead to incorrect 497 conclusions about the usefulness of certain ... done using the SPSS software (SPSS Inc., Chicago, IL, USA, version 11.5) All tests were two-sided with a significance level of 0.05 Results Description of studies A total of 4695 studies were...

Ngày tải lên: 25/10/2012, 10:51

... vertical side of still was kept as 0.30 m, whereas the height of higher vertical side was kept 0.85 m The effective basin area of meter x meter made of GRP of m thickness Condensing cover made of toughed ... experimental set up of single slope solar still Experimental set up consists of condensing cover of 30 degree fabricated to accommodate 0.20 m water depth maximum The bottom surface of the still was ... cover made of toughed glass of mm is fixed to the top of vertical walls of the stills using a rubber gasket on both sides of glass and clamp fixed iron frames made of angles A plastic pipe is...

Ngày tải lên: 05/09/2013, 15:28

... proximity of the metal nanoparticles A lower barrier height at the metal -semiconductor interface facilitates the flow of electrons from the semiconductor into the metal, which lowers the magnitude of ... absorption, calculation of the absorption and scattering cross sections of the Au nanoparticles, comparison of nanoparticles in solution with those adsorbed onto an electrode, Au nanoparticles deposited ... electrolyte -semiconductor interface; this often is caused by a high concentration of surface states at the metal -semiconductor interface that results in Fermi level pinning.19 Because the basis of the...

Ngày tải lên: 18/09/2013, 21:26

... the current was turned off for a fixed duration toff of 0.5 s During ton, FePt nanoparticles were deposited on the surface of the electrode When the current was switched off, an ultrasound was ... magnetization of the unannealed particles was about few emu/g and the coercivity was 20 – 80 Oe The low value of Ms of the as-prepared nanoparticles may be explained by the oxidation or hydroxidation of ... to make FePt magnetic nanoparticles FePt nanoparticles made by this technique had the size of 10 - 20 nm After annealing, the nanoparticles N.H Luong et al / VNU Journal of Science, Mathematics...

Ngày tải lên: 13/02/2014, 03:20

... structural determination With small amounts of material (e.g a few picomoles), no single analytical technique is capable of the complete characterization of an oligosaccharide structure Structure ... different techniques, of which MS and NMR are two of the most powerful Previously, we demonstrated the distinction of chain type and blood-group type (such as Lea/x and Leb/y) of underivatized oligosaccharides ... this report, we demonstrate our strategy of the combined use of ES-MS and NMR for analysis of the core-branching pattern and full sequence assignment of four oligosaccharides isolated from human...

Ngày tải lên: 19/02/2014, 12:20

... subunit analysis of single deletion mutants We sought to determine how the absence of individual supernumerary subunits affected the composition of bc1 Table Growth phenotype of single and double ... [28] Results Growth phenotype of single and double deletion mutants The growth phenotype of the yeast strains with deletions of genes encoding various subunits of the bc1 complex was determined ... subunits of the yeast bc1 complex indicated on the left side of the blots Ó FEBS 2004 Assembly of the yeast cytochrome bc1 complex (Eur J Biochem 271) 1213 Table Cytochrome bc1 subunit analysis of single...

Ngày tải lên: 19/02/2014, 12:20

Ngày tải lên: 15/03/2014, 23:15

... from the distal point of the rest of the protein Such a dipole will have weak interactions with the rest of the protein Thus, if turned off (by removal of Arg and protonation of Asp185), the protein ... of microgram quantities of protein utilizing the principle of proteindye binding Anal Biochem 72, 248254 30 Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head of ... parameters of E coli CMP kinase variants with three NMP substrates at a single xed concentration of ATP (1 mM) Curve-t was performed using the nonlinear least-squares tting analysis of KALEIDAGRAPH software...

Ngày tải lên: 16/03/2014, 10:20

... electron microscopic image of the morphology of the SiNWs It was observed that the product exemplified high purity with a uniform diameter 20 nm and consisted of most of the SiNWs aligning on the ... Fig shows a high resolution TEM (HRTEM) image of a single SiNW with a diameter of about 18 nm The (1 1) lattice fringes with the interplanar spacing of 0.31 nm and the corresponding selected area ... shows the Raman scattering spectra of the SiNWs and crystal silicon A very sharp and Fig A typical SEM image of the morphology of aligned silicon nanowires of uniform diameter distribution on...

Ngày tải lên: 16/03/2014, 15:06

... Fig 1(b) indicates the amoeba-shape of the nanowires, with the diameter of about 70 nm and a length up to tens of micrometers Fig 1(c) shows frog-egg morphology of the nanowires, which is similar ... nanowires [17] The growth of the nanowires Fig XPS of the sample (a) survey spectrum of the sample; (b) Si2p binding energy spectrum; (c) O1s binding energy spectrum Fig PL spectrum of the SiONWs at room ... combination of di€erent nucleation and growth processes can give rise to di€erent forms of SiONWs, which is similar to the growth model of Si nanowires [20] The formation process of polyp-shaped...

Ngày tải lên: 16/03/2014, 15:07

... Experiment Fig TEM image of Si nanoparticles by cathode arc plasma Before the preparation of producing SiNWs, Si nanoparticles were synthesized by cathode arc plasma which is one of the most powerful ... image of Si nanoparticles after heat treatment at 980 °C without Fe catalysts and (b) nanowires with Fe, (c) TEM image showing nanopartical catalysts at the end of nanowires (d) TEM image of an ... image showing catalysts at the end of nanotubes, (b) TEM image of an individual nanotube and SAED pattern investigate the structure and morphology of the Si nanoparticles and nanowires Results...

Ngày tải lên: 16/03/2014, 15:13

... average resistivity of all heavily doped (1019 cm−3 ) nanowires is found to be 83 m cm, a value higher by a factor of 14 than expected from the design data of m cm (a factor of for the largest ... than a threshold of −2:7 V [11,12] The ambient humidity is kept constant at a level of 30 – 40% Applying a tip voltage while the tip is scanned over the silicon surface at speed of 0.1– m=s leads ... ultra-thin single- crystal silicon top layer (typically 15 –20 nm) were used One advantage of this technology is that it ensures a very sharp interface top silicon layer–silicon dioxide (see inset of...

Ngày tải lên: 16/03/2014, 15:15