Optical limitng and field emission studies of carbon nanotubes

... OPTICAL LIMITING AND FIELD EMISSION STUDIES OF CARBON NANOTUBES GOHEL AMARSINH B.Sc (Hons.) SUPERVISOR A/PROF ANDREW WEE THESIS SUBMITTED FOR THE DEGREE OF MASTER OF SCIENCE DEPARTMENT OF ... investigate two of carbon nanotubes most well known properties: optical limiting and field emission Our aim is to modify the carbon nanotubes using physical and c...

Ngày tải lên: 27/11/2015, 12:23

... variety of nanostructured carbon films ranging from diamond [24], carbon nanosheets [25] CNTs [20, 23], and carbon nanobells [26, 27] to monochiral MWNTs [28] on Si substrates This technique offers ... treatment of Fe film on such substrates These particles probably seeded the nucleation and growth of CNTs Surface morphology of CNT films deposited on such substrates i...

Ngày tải lên: 22/06/2014, 01:20

... consisted of the a-Fe2O3 Fig The I–V characteristics of (a) the ITO /a-Fe2O3 film /a-Fe2O3 NW/ CAFM-tip structure and (b) the ITO /a-Fe2O3 film /CAFM-tip structure Fig The CAFM images of (a) morphology and ... 108 NWs/cm2 123 332 Fig (a) TEM image of an a-Fe2O3 NW, (b) HR-TEM image of the a-Fe2O3 nanowire, and the SAED pattern of the a-Fe2O3 NW (inset) for sample C,...

Ngày tải lên: 20/03/2014, 13:08

... that the emission area in this high field region not changed, and the stability of field emission is high The slopes and intercedes of these plots in the high field region are the same, showing the ... AlQ3 Conclusions In conclusion, the field emission properties for Ag-TCNQ nanostructured array were dependent on the structure and morphology determined by th...

Ngày tải lên: 21/06/2014, 17:20

... consisted of the a-Fe2O3 Fig The I–V characteristics of (a) the ITO /a-Fe2O3 film /a-Fe2O3 NW/ CAFM-tip structure and (b) the ITO /a-Fe2O3 film /CAFM-tip structure Fig The CAFM images of (a) morphology and ... 108 NWs/cm2 123 332 Fig (a) TEM image of an a-Fe2O3 NW, (b) HR-TEM image of the a-Fe2O3 nanowire, and the SAED pattern of the a-Fe2O3 NW (inset) for sample C,...

Ngày tải lên: 22/06/2014, 01:20

... FIELD EMISSION STUDIES OF NANOMATERIALS Submitted by: TEO CHOON HOONG (B.Sc (Hons), NUS) Supervisor: A/PROF SOW CHORNG HAUR A THESIS SUBMITTED FOR THE DEGREE OF MASTERS OF SCIENCE ... factor and area factor of the various CuO nanorods before and after laser patterning 46 5.1 Turn-on field and threshold field for various field emitters 60 6.1 Studies of field emiss...

Ngày tải lên: 06/10/2015, 20:56

... et al Figure Morphology of CNTs grown under different dc bias voltages FESEM images of CNTs grown under (a) -200 V, (b) -100 V, and (c) V (d) TEM images of CNTs grown under V (inset shows a higher ... spectra of CNTs grown under negative and zero dc bias voltage represent sp3 rich phases of CNTs and suggest the existence of amorphous carbon or def...

Ngày tải lên: 06/05/2014, 08:53

... of monogalactosylated serine and arabinosylated hydroxyproline Dispersion of SWNTs in YK20 solutions About mg of HiPCO carbon nanotubes (carbon nanotechnology Inc.) were added to a solution of ... the condensed aggregates opened up and displayed the random networks of linear fibrils Since the polyproline-II helix is a left-handed helix with about residues per turn and a pi...

Ngày tải lên: 22/06/2014, 22:20

... layer porous carbon paper which consists of a macroporous layer of carbon fiber paper (SGL, Germany) and a microporous layer of carbon black powder and a hydrophobic agent The carbon black powder ... enhances an intimate electronic contact between the CNTs and the macroporous carbon paper The graphitized carbon paper was prepared by deposition of a mixture of carbo...

Ngày tải lên: 22/06/2014, 18:20

... any of the above reports This is important because CNTs prepared by low temperature plasma CVD process have many structural defects For example, CNTs prepared by PECVD process using any hydrocarbon ... TEM micrographs of short conical CNTs (a) low magnification image, (b) magnified view of the shortest conical CNTs, (c) highly magnified view of tip, and (d) typical HRTE...

Ngày tải lên: 22/06/2014, 06:20

... any of the above reports This is important because CNTs prepared by low temperature plasma CVD process have many structural defects For example, CNTs prepared by PECVD process using any hydrocarbon ... TEM micrographs of short conical CNTs (a) low magnification image, (b) magnified view of the shortest conical CNTs, (c) highly magnified view of tip, and (d) typical HRTE...

Ngày tải lên: 22/06/2014, 19:20

... Thesis Title: PREPARATION, CHARACTERIZATION AND PROPERTY STUDIES OF CARBON NANOSTRUCTURES DERIVED FROM CARBON RICH MATERIALS Abstract Carbon nanomaterials have always been an area of interest for ... amorphous carbon Physical and chemical properties of carbon vary in each of the allotropes For example, diamond is one of the hardest materials existin...

Ngày tải lên: 10/09/2015, 15:48

... Background 1. 2 Carbon Nanotubes 1. 2 .1 Discovery of Carbon Nanotubes 1. 2.2 Bonding Structures of Carbon Nanotubes 1. 2.3 Properties of Carbon Nanotubes 1. 2.4 Applications of Carbon Nanotubes 2 13 1. 3 ... Nanostructures 10 6 5.2.5 FE Study of Tungsten Oxides Coated CNT Nanostructures 11 0 5.2.6 Summary 11 4 References 11 5 CHAPTER FIELD E...

Ngày tải lên: 11/09/2015, 10:17

... [9-13] 22 Chapter Physics of Field Emission -4 ln ( J/E2) Current density, J ( mA/cm2) -2 -6 -8 -10 - 12 -14 0 .2 0.3 0.4 0.5 1/E 0 Applied electric field, E ( V/µm) Fig 2. 2 The electron emission ... Proc 91, 429 (20 08) 29 Chapter Physics of Field Emission 20 C S Chang, S Chattopadhyay, L C Chen, K H Chen, C W Chen, Y F Chen, R Collazo, and Z Sitar, Phys Rev B 68, 125...

Ngày tải lên: 11/09/2015, 10:17

... the acquisition time per spectrum of ~150 s 3. 4 Field Emission Apparatus Field emission testing of the samples was carried out with a custom-designed field emission system, using parallel plate ... ionization and emission of a core (inner shell) electron whereas in UPS the photon interacts with valence levels of the molecule or solid, leading to ionization by remova...

Ngày tải lên: 11/09/2015, 10:17