Field emission studies of nanomaterials

... 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

... 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

... electron field emission characteristics Appl Surf Sci 2004, 221:38 doi:10.1186/1556-276X-6-176 Cite this article as: Zhao et al.: Field emission enhancement of Au-Si nano-particle-decorated silicon ... potential barrier height of emitter Conclusions Au film coating on the tip of SiNWs reduces the FE properties of SiNWs because of Au having high work function Well-ali...

Ngày tải lên: 21/06/2014, 05:20

... 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

... electrons are emitted from the graphene tip creating an electron current that can be modulated on and off Fig Fabrication process of graphene sheets using a mechanical exfoliation method The graphene ... vacuum chamber, two tungsten tips were located on the graphene sample; one was contacted directly to the sample and grounded as a cathode, and the other was placed an arbi...

Ngày tải lên: 22/06/2014, 00:20

... 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: 22/06/2014, 01:20

... 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

... 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, 19:20

Ngày tải lên: 13/11/2014, 10:09

... 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

... heater Fig 4. 1 Schematic setup of the PECVD system used 55    Chapter Synthesis of Vertically-Aligned Carbon Nanotubes 4. 3 Results and Discussion 4. 3.1 Characterization of the As-Grown Carbon Nanotubes ... covered with amorphous carbon, which is the product of the thermal deposition of hydrocarbon [3] 52    Chapter Synthesis of Vertically-Aligned Carbon Nanotubes...

Ngày tải lên: 11/09/2015, 10:18