Dissertation > Excellent graduate degree dissertation topics show

Investigation on the Preparation and Properties of One-Dimensional ZnO Nanomaterials by Water Bath Method

Author: LiLin
Tutor: WangXueWen
School: Northwestern University
Course: Microelectronics and Solid State Electronics
Keywords: One-dimensional ZnO nanomaterials Water bath method Photoluminescence Field emission
CLC: TB383.1
Type: Master's thesis
Year: 2009
Downloads: 254
Quote: 5
Read: Download Dissertation

Abstract


ZnO is an important wide band semiconductor with a band gap of 3.37eV and exciton banding energy of 60meV,which have extensive application for fabricating microelectronics and optoelectronics devices.The more considerable attention on ZnO nanomaterials because of its special electric,optical,magnetic properties.In this paper,the aqueous solution of zinc nitrate（Zn（NO3）2） reacted with the aqueous solution of equimolar methenamine （（CH2）6N4） by using water bath method.ZnO nanostructure with different morphologies were prepared on Si substrates and surface treated Si substrates.With the different growth condition, ZnO nanostructure with controllable morphologies were successfully prepared.ZnO nanorods,nanorod arrays,nanoparticles, nanosheets,nanotubes were prepared by changing the concentration of solution,reaction time, reaction temperature,pH value and substrates. The ingredient,surface feature and crystal structure of the samples are characterized by XRD, SEM and EDS.The growth mechanism of ZnO nanostructure is investigated in detail.The ZnO nanorod arrays are characterized by XRD and PL spectrum.Annealing, Al3+ doping and Co2+ doping play a important role in the crystal structure and photoluminescence properties of ZnO nanorod arrays.The intensity of characteristic luminescent peaks increases after Annealing, Al3+ doping and Co2+ doping.With the increase of doping concentration, The intensity of characteristic luminescent peaks increase flrst,but then decrease. And there is a little red shift due to quantum size effect.The samples with Co2+ doping could more effectively improve the intensity of characteristic luminescent peaks.Their luminescence mechanisms and the reason of red-shift have been explained.These investigations provide a lot of experimental and theoretical foundations for fabricating optical devices,which based on ZnO nanorod arrays.Field emission properties are investigated on ZnO nanorod arrays,which are prepared in different concentration of solution and substrates.The shielding effect weaken between ZnO nanorods and has better electron emission properties when the concentration of solution is 0.01 mol/L.The field emission properties enhance after gilding or copperizing on Si substrates. Because it can provide more emission electrons and good conducting channel.The key factors have been discussed by SEM and facula test.Then provide some methods to enhance field emission properties.It illuminates that the ZnO nanorod arrays,which are prepared by water bath method has perfect field emission properties and can be used as field emitters.It has great development foreground in field emission application.

Related Dissertations

  1. Eu- doped α-SiAlON phosphor First-principles study,TB34
  2. Terphenyl liquid crystal containing chiral polyacetylene Synthesis and Properties,O631.3
  3. CNT surface metal electrode implantation method and its application technology research,TB383.1
  4. Preparation of phase separation of the amorphous silicon oxide and nanocrystalline silicon mosaic silica,TN304.1
  5. The Influence of Field Penetration to N-type Silicon Field Emission Electron Spectroscopy,O463.1
  6. Optical Properties of Zn-based Quantum Dots and Application in LED,O471.1
  7. Luminescence Properties of Thenardite Activated with Eu and Tb,O482.31
  8. Study on Preparation and Properties of Fluorescent Offset Printing Ink,TS802.3
  9. Carbothermal reduction and the preparation of silicon carbide nanowires its performance,TB383.1
  10. Surface deposition of copper thin film of porous silicon , Preparation and luminescence characteristics of,TB383.4
  11. Hydrothermal Preparation and characterization of nano - ZnO and yttrium aluminum garnet,TB383.1
  12. Controllable Growth and Properties of ZnO Nanorod Arrays,TB383.1
  13. Study of Field Emission Properties of Printed Carbon Nanotube Films,TB383.1
  14. Preparation and Luminescence Properties of SnO2 Nano-materials and Eu3+-doped SnO2 Nano-Particles,TB383.1
  15. The Synthesis of Aluminate (Silicate) Materials by Molten Salt Process and Their Photoluminescence,TQ422
  16. Measurements Combine Electroluminescence with Photoluminescence and Analog Simulation of PET,O631.23
  17. The Infrared Emissivity and Photoluminescence of Rare Earth Doped ZAO Ceramics,TQ174.75
  18. Study on the Synthesis and Optical Properties of New Inorganic Luminescent Materials Co-doped with Rare Earth Ions,O611.4
  19. The Summarization and Improvement of the Spin-polarized Electron Collision Apparatus,TH838.5
  20. Study on Spectral Characteristics of CdSe/ZnS-Quantum-Dot Doped Fibers with High Doping Concentrations,TN253
  21. Study on Synthesis and Luminescent Properties of LaPO4:Eu3+ Nano-materials,TB383.1

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net  Mobile