Dissertation > Excellent graduate degree dissertation topics show

Quantum Dots Interface Modification&Sensitization and Their Photovoltaic Characteristic

Author: MaZuoZuo
Tutor: WangLiZuo
School: Tsinghua University
Course: Chemistry
Keywords: dye-sensitized solar cells quantum dots interface modification photocatalytic synthesis electron injection and recombination
CLC: O649
Type: PhD thesis
Year: 2012
Downloads: 216
Quote: 0
Read: Download Dissertation

Abstract


Quantum Dots sensitized solar cells have be considered as one of the advancedresearch topics in the field of solar cells, since its’ tunable spectral response range, highextinction coefficient and higher theoretical conversion efficiency. This dissertationtargeted at several main scientific issues in the field of quantum dots in sensitized solarcells, and launched a series of studies on PbS quantum dots interface modification ofphotoanode, new photocatalytic synthesis of PbS quantum dots, electron injection andphotovoltaic characteristic of core-shell quantum dots. The main results and conclusionsof this dissertation are as follows:(1) PbS quantum dots synthesized by in-situ method were used for interfacemodification of TiO2photoanode. The photovoltaic characteristic results indicated thatthe PbS quantum dots with3prepar-circles showed the photoelectric conversionefficiency improved21%. According to the results of transient photovoltage spectra,dark current measurement and surface photovoltage spectroscopy, after PbS quantumdots interface modification, the traps on surface of TiO2, known as “surface states”, wasextremely reduced due to the presence of PbS, therefore the charge recombination wasretarded significantly. And then structure and morphology of the PbS quantum dotswere studied by X-ray diffraction (XRD) analysis, BET physisorption andhigh-resolution transmission electron microscope (HR-TEM). The results showed that2-3nm PbS quantum dots particles formed the major part of the particles. The certaindistribution of the particles sizes is benefit for filling the surface states of TiO2films.(2) Since the currently synthesis methods of quantum dots shows problems such asrelatively low adsorption, nonuniformity size distribution and lots of toxic waste. PbSquantum dots were synthesized by an in-situ photocatalysis method using thephotocatalytic activity of nanocrystalline TiO2films. The synthesis kinetics and reactionmechanism was discussed. The effective mass approximation calculation showed thatsize of the synthetic quantum dots is about1.7nm under1.8mW/cm2UV illuminationfor10minutes. The PbS quantum dots achieved showed good sensitization ability, andin the meantime this method is much more simple and environmentally friendly.(3) The electron injection and recombination and the relative photovoltaic characteristic for shell-thickness dependent CdSe/ZnS core-shell quantum was studied.The study results suggested that both the injection and recombination rate slow downwith the increasing of shell-thickness, until the thickness reached2molecular layers,when the decay rate begin remain a certain value. The corresponding quantum dotssensitized solar cells showed better photoelectric conversion efficiency and stability atthe same shell thickness.

Related Dissertations

  1. Investigation of Preparation and Properties of Ordered Porous TiO2,TB383.2
  2. Research on the Interface Modification of Epoxy Resin/Metallic Substrates and Epoxy Resin/Pigment,TQ630.1
  3. The Effects of Exposure to Bisphenol-a between Adolescence and Early Adulthood on Behaviors in Mice and Its Molecular Mechanism,R965
  4. Pyridine Metal Complexes electronic spectra and redox properties of theoretical research,O627
  5. The Study of the Hydrogenic Impurity States in Symmetric Couple Quantum Dots,O471.1
  6. The Transport and Optical Properties of Single-electron Tunneling Coupled Quantum Dots,O471.1
  7. Full Counting Statistics in Side-coupled T Shaped Double Quantum Dots,O469
  8. The Electron Dynamics and Transport Properties in the Coupled Double-Quantum-Dot System,O471.1
  9. Functionalized CdSe/CdS Quantum Dots as Fluorescent Probes for the Detection of Heavy Metal Ions,O657.3
  10. Net Signal Spectral Analysis of Multi-component Drugs and Polyelectrolyte Protection of Quantum Dots and Its Application in Nucleic Acid Detection,R91
  11. Studies on the Synthesis of Water-soluble Quantum Dots Modified by PEG and the Interaction with Peptide,O471.1
  12. The Synthesis of Luminescent Magnetic Nanoparticles and Their Applications in Bioanalysis,TB383.1
  13. Theoretical Study on the Electronic Properties in Semiconductor Quantum Wires and Quantum Dots,O471.1
  14. Design and Applications of turn-on Fluorescent Probe Based on the Surface Structure of Quantum Dots Modulated Using Suitable Chemical Agents,O657.3
  15. PbSe Quantum Dot-Doped Silicate Fiber Materials by Melting Method,TN304
  16. The Synthesis of Structural Controllable Titanium Dioxide Nanorods Array and Its Electrochemical Performance,TB383.2
  17. Dssc Light Anode Preparation and Performance Study,TM914.4
  18. Preparation of Titanium Nanocrystals from Titanium (Ⅳ) Bis (Ammonium Lactato) Dihydroxide and Their Application in DSSCs,TB383.1
  19. The Research of the Dye-Sensitized Nanocrystalline TiO2 Solar Cells,TM914.4
  20. Preparation 3DC_f/SiC vapor infiltration of silicon structure, performance and interface Regulation,TB332
  21. TiO 2 nanocrystalline porous anodic film synthesis and optical properties of the photoelectric conversion,TM914.4

CLC: > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Semiconductor chemical
© 2012 www.DissertationTopic.Net  Mobile