growth structures and optical properties of iii nitride quantum dots

... Nonlinear optical properties of quantum dots: excitons in nanostructures J Nonlinear Opt Phys Mater 2009, 18:195 Gotoh H, Kamada H: Coherent nonlinear optical properties in quantum dots NTT Tech ... difference of 5.237 meV, while for the first and second excited states the differences are of 3.472 and 2.784 Table Eigenenergies of the exciton and peak energies of the OR and SHG coefficients with and ... electron and the hole increases, and therefore the Coulomb interaction decreases, as the energy of the quantum state increases The final result is a blue-shift of the OR and SHG peaks of the order of...

Ngày tải lên: 21/06/2014, 04:20

... studied the growth angle effect of the films for optical properties The thickness of the ZnO thin films was checked by FE-SEM and was fixed at 100 nm Three growth angles (0°, 15°, and 30°) of the ... with various growth angles ZnO films at (a-1) 0°, (b-1) 15°, and (c-1) 30° growth angles and their enlarged images (a-2, b-2, and c-2) Figure shows the XRD patterns and grain sizes of the ZnO films ... on average and low values The transmittance and reflectance are slightly changed by the growth angle of ZnO films Figure shows the reflectance patterns of the ZnO films with different growth angles...

Ngày tải lên: 21/06/2014, 17:20

... effects of size and shape of Si-nc on the incorporation of group -III (B and Al), group-IV (C and Ge) and group-V (N and P) impurities Single-doping has been investigated both in spherical and faceted-like ... asymptotically the value of the band-gap of the undoped Si-nw This is another indication of how doping can modify the electronic and optical properties of the Si nanostructures Conclusions 3.2 ... the FE and the electronic properties of the Si-nc are influenced by the insertion of more and more impurities We call this insertion of several impurities multidoping Fig shows how the FE of a large...

Ngày tải lên: 16/03/2014, 15:15

... in terms of the projection of energy band in bulk Si and confinement effect: the confinement decreases the energy of HO states and increases the energy of the LU states, but the magnitude of the ... is 1.5 Â 10À3 e/Å3 The wave functions of p- and p*-like bands on Si(1 1)-(2 Â 1) surfaces are also shown on the inset of (a) and (b), respectively p*-like bands on {1 1} facets, respectively This ... energy of nanowire in the supercell, lSi (lH) is the chemical potential of an Si (H) atom, nSi (nH) is the number of Si (H) atoms, and ez is the zero-point energy of Si–H vibrations The value of...

Ngày tải lên: 16/03/2014, 15:37

... and the intensity of this peak increases relative to that of UV emission as the length of nanorods increases A similar PL pattern with two emission maxima, yet at much lower energies of 2.8 and ... band gap due to impurities.22b In light of these assignments, we suggest that the UV emission of nanorod samples in this work might correspond to the band-toband transition The blue emission of ... COMMUNICATIONS Comparing the intensities of the (010) and (014) peaks of the sample with those of the bulk W18O49, it was found that the relative intensity of (010) has been dramatically increased...

Ngày tải lên: 20/03/2014, 13:08

Ngày tải lên: 22/03/2014, 11:20

... SAED pattern of the sea urchin-like ZnO nanostructures are presented in Fig Fig 2a and b displays the low magnification and high magnification SEM images of the sea urchin-like ZnO nanostructures, ... pattern (a) and UV–visible optical absorption characteristics (b) of the sea urchin-like ZnO nanostructures Fig SEM images (a,b), TEM image (c), HRTEM image (d) and SAED pattern (e) of the sea ... of Fig 2d For analyzing the photoelectric properties of the sea urchin-like ZnO nanostructures, simple battery devices were fabricated Fig shows the I–V curve of the sea urchin-like ZnO nanostructures...

Ngày tải lên: 06/05/2014, 13:23

... Thus the control of structural type and composition of bimetallic nanoparticles comprised of Ag and Au have been a subject of considerable interest; and the developed of simple and versatile methods ... the scattering coefficients an and bn, and are function of particle radius, and light wavelength λ (in terms of the Ricatti-Bessel functions) As the absorption band of noble metal nanoparticles ... frequency and intensity of SPR band depend on the size, shape, structure and composition [39,40,45] of the metal nanoparticles While the techniques like TEM, HREM reveal the exact size and shape of...

Ngày tải lên: 04/06/2014, 15:20

... structural and optical properties of type-II GaSb/InGaAs quantum dots [QDs] grown on InP (100) substrate by molecular beam epitaxy Rectangular-shaped GaSb QDs were well developed and no nanodash-like structures ... Medeiros-Ribeiro G: Optical and structural properties of InAsP ternary self-assembled quantum dots embedded in GaAs Appl Phys Lett 2002, 81:2953 15 Liu G, Chuang S-L, Park S-H: Optical gain of strained ... Figure AFM and STEM images of GaSb/In0.53Ga0.47As QDs and histogram of the height of GaSb/In0.53Ga0.47As QDs (a) The AFM image of GaSb/In0.53Ga0.47As QDs, (b) histogram of the height of GaSb/In0.53Ga0.47As...

Ngày tải lên: 20/06/2014, 20:20

... migration of the sputtered atoms, thus forming a denser film with larger grains and lower defects Optical properties The optical transmittance spectra in the wavelength range of 200 to 1,100 nm of ZnS ... value The optical band gap of the film deposited at 100°C was 3.45 eV As the growth temperature increased from 200°C to 350°C, the optical band gap red-shifted from 3.57 to 3.79 eV The band gaps ... designed and carried out the experiments and wrote the first draft of the manuscript JHA analyzed the properties and helped draft the manuscript KNH and KSH detailed the original idea and modified...

Ngày tải lên: 20/06/2014, 21:20

... acceptor/donor impurities and is helpful in understanding the optical and electrical performances of the materials We focused on the temperature-dependent PL measurements of various silver-doped ... in acetone and methanol for 20 and rinsed in de-ionized water for The 1, 3, and wt % SZO (5SZO) NWs are grown in a furnace at 800°C with argon gas of 90 sccm and a working pressure of 1.2 torr ... structural and (a) (b) optical properties of the nanostructures were investigated by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and low temperature...

Ngày tải lên: 20/06/2014, 22:20

... functional groups [32,33] Also, the silica shell can enhance the optical properties of the nanoparticles [34] The optical properties of the nanostructures have been investigated earlier using many techniques, ... objective of this study is to investigate the effect of Zn2+ partially substituting for Co2+ in CoFe2O4 nanoparticles (Co1-xZnxFe2O4; x = 0, 0.5, and 1) and shelling with silica on the magnetic and optical ... optical properties of the ferrite nanoparticles for a variety of magneto -optical nanodevice applications From a synthesis point of view exploring the effect of firing temperatures (400°C, 600°C and...

Ngày tải lên: 21/06/2014, 01:20

... well-established knowledge of the electrical and optical properties of GaSe thin films, in this paper, we report the results on electrical and optical measurements of amorphous thin films of GaSe nanorods ... frequency doubling and fast optical gating [11] and behaves as an X-ray detector [12] Electronic and optoelectronic properties of GaSe, GaS, and InSe materials indicate the possibilities of realizing ... field of micro/optoelectronics Significant research efforts have been focused to the study of the electrical and optical properties of this compound in thin film formation Since the optimization of...

Ngày tải lên: 21/06/2014, 17:20

... GaSb/In0.53Ga0.47As QDs and histogram of the height of GaSb/In0.53Ga0.47As QDs (a) The AFM image of GaSb/In0.53Ga0.47As QDs, (b) histogram of the height of GaSb/In0.53Ga0.47As QDs, and (c) the STEM image of GaSb/In0.53Ga0.47As ... Medeiros-Ribeiro G: Optical and structural properties of InAsP ternary self-assembled quantum dots embedded in GaAs Appl Phys Lett 2002, 81:2953 15 Liu G, Chuang S-L, Park S-H: Optical gain of strained ... The structural and optical properties of GaSb/InGaAs type-II quantum dots grown on InP (100) substrate Nanoscale Research Letters 2012 7:87 Submit your manuscript to a journal and benefit from:...

Ngày tải lên: 21/06/2014, 17:20

... GaSb/In0.53Ga0.47As QDs and histogram of the height of GaSb/In0.53Ga0.47As QDs (a) The AFM image of GaSb/In0.53Ga0.47As QDs, (b) histogram of the height of GaSb/In0.53Ga0.47As QDs, and (c) the STEM image of GaSb/In0.53Ga0.47As ... Medeiros-Ribeiro G: Optical and structural properties of InAsP ternary self-assembled quantum dots embedded in GaAs Appl Phys Lett 2002, 81:2953 15 Liu G, Chuang S-L, Park S-H: Optical gain of strained ... The structural and optical properties of GaSb/InGaAs type-II quantum dots grown on InP (100) substrate Nanoscale Research Letters 2012 7:87 Submit your manuscript to a journal and benefit from:...

Ngày tải lên: 22/06/2014, 00:20

... composed of stannum and sulfur, and the ratio of the S atom and Sn atom is 1:0.985, which just accords with the stoichiometric ratio of SnS The representative optical absorption spectrum of the ... = and 2/3 for direct allowed and forbidden transitions, respectively, and n = 1/2 and 1/3 for indirect allowed and forbidden transitions, respectively Figure shows curves of (ahm)2 versus hm of ... 361 Fig SEM images of AAO template and SnS nanowire arrays a Typical SEM image of AAO template b and c The top view in a low magnification d SEM image of a typical crosssection and uniformly distributed...

Ngày tải lên: 22/06/2014, 01:20

... characterisation, the use of Raman microscopes is now widely used because it offers a non-destructive and quantitative microanalysis of structures and electronic properties Because of its higher resolution ... application of identification of compounds, there are a large number of reported works on the characterisation of concentration and mobility of free carriers, strain and crystal quality, determination of ... the lower edge of the O2p-like valence band and extend almost through the whole band Whereas, the uppermost valence band edge consists of pz-type states that form the lone pair (out -of- plane) π...

Ngày tải lên: 08/09/2015, 15:20

... MAGNETIC AND OPTICAL PROPERTIES OF ATOMICALLY CONTROLLED COMPLEX OXIDE HETEROSTRUCTURES AND INTERFACES XIAO WANG (B.Sc, Shandong University, P.R China) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF ... in either of the bulk materials However to fully utilize these materials and structures, exploration of the properties, understanding of the underlying mechanisms and novel designs of possible ... der Merwe growth, Volmer-Weber growth, Stranski-Krastanov growth and step flow growth [60] Wetting will dominate if free energy of substrate is higher than the total of that of thin film and interface,...

Ngày tải lên: 09/09/2015, 10:07

... Electronic, optical and vibrational properties of TMDCs Electronic structure The band structures of many TMDCs have been calculated by using first principles and tight-binding approximation approaches and ... background and literature review 1.1.1 Synthesis of 2D TMDCs 1.1.2 Electronic, optical and vibrational properties of TMDCs Electronic structure Optical properties ... Group，Copyright 2013 Optical properties The effect of the bandgap transition on optical properties in 2D TMDCs has been investigated through optical reflection, Raman scattering, photoconductivity and photoluminescence...

Ngày tải lên: 09/09/2015, 11:16

... lot of people have helped me to further my research and I am grateful to all of them Especially, I would like to sincerely thank my supervisors Prof Ariando and Prof T Venkatesan for educating and ... the source of confidence and strength in my research and life iii Table of Contents Acknowledgements i Table of Contents iv Abstract viii List of Publications ... (b) Photograph of one of PLDs in our lab 22 Figure 2.2 Schematics of 2D growth modes: step-flow growth and layer-bylayer growth 25 Figure 2.3 Schematic of the Ewald’s...

Ngày tải lên: 10/09/2015, 09:11