Dissertation > Excellent graduate degree dissertation topics show

Theoretical and Experimental Research on Cu（InxGa1-x）Se2and Cu2ZnSn（S/Se）4Solar Cell Thin Films

Author: LiMiaoMiao
Tutor: ChangFangGao; WangTianXing
School: Henan Normal
Course: Materials Physics and Chemistry
Keywords: magnetron sputtering CIGS Se target DFT electrical characteristics opticalproperties
CLC: TM914.4
Type: Master's thesis
Year: 2012
Downloads: 207
Quote: 0
Read: Download Dissertation

Abstract


Cu(InxGa1-x)Se2and Cu2ZnSn（S/Se）4solar cells are the representative photovoltaic device withlow cost, stability and high efficiency. After more than30years development, the highest conversionefficiency of Cu(InxGa1-x)Se2is up to20.3%, but it did not realize industrialization because of the difficultyto prepare absorbing layer CIGS which plays an important role in the CIGS solar cell. As a result of In andGa are costly metals, scientists are looking for the new elements to replace them. CZTS and CZTSe are thepromising alternative materials, the electronic structure and optical properties of which have beencomputed by the density functional theory （DFT）.This thesis was divided into two parts. In the first part, CIGS thin films were prepared bymagnetron sputtering. The crystal structure, surface morphology and composition ratio were measured byX-ray diffraction （XRD）, atomic force microscope （AFM）, scanning electron microscope （SEM） andenergy disperse spectroscopy （EDS）, respectively. Also, we explored the optimum condition of backelectrode layer, buffer layer and window layer. In the second part, the geometry structure parameters ofCu2ZnSnS4（CZTS） and Cu2ZnSnSe4（CZTSe） were optimized by means of plane wave ultrasoftpseudo-potential method with generalized gradient approximation （GGA） under the density functionaltheory （DFT）. The density of states, adsorption coefficient, dielectric function, refractive index, reflectivity,conductivity and loss function were also calculated. The results indicate that:（1） The growth and crystallization of CIS thin films are largely rely on the sputtering andannealing temperature. As the substrate temperature gets higher, the mobility of the sputtering particles isenhanced to restrain the dislocation at the interface and improve the crystallization. The results show thatCIS thin films with high crystallinity have been achieved by annealing at560℃, and570℃.（2） The chalcopyrite structure, good surface morphology and proper stoichiometric ratio for theCIGS thin films were obtained by sputtering CuIn, CuGa and Se targets with high substrate temperature.（3） The calculated results show CZTS and CZTSe crystals are both direct band gap materials andCZTS is0.5eV larger than CZTSe, which is closer to the optimized band gap.（4） CZTS and CZTSe have absorption peaks with105cm-1orders of magnitude in the UV-light. In the visible light, the absorption coefficient of them exceeds104cm-1and CZTSe is a little higher than CZTS,which is an advantage in the solar cells.（5） The band gap of CZTS is larger than CZTSe, making the dielectric function curve slightlymove to the direction of high energy. These peaks of the curves are closely related to the direct or indirecttransition of electrons.

Related Dissertations

  1. Density Functional Theory Study of Dimethyl Ether Adsorption on the Low-Index Pt Surface,O485
  2. The Algorithm of DFT with a Subset of Output Points Based on TS101 and Its Software Implementation,TN911.72
  3. LSGM electrolyte thin films and electrochemical properties of,TM911.4
  4. Hydrogen complex photochemical Theoretical Study,O641.1
  5. Pyridine Metal Complexes electronic spectra and redox properties of theoretical research,O627
  6. Research on CIGS Thin-Film Solar Cell Made by Magnetron Sputtering,TM914.4
  7. The Study of Hemocompatibility of Fluorinated Diamond-like Carbon Films,R318.08
  8. The Oxygen Reduction Activity of the Pt-Based Catalyst: First Principles Study,TM911.4
  9. The Microwave Properties of c-axis Oriented BaFe12O19 Films Sputtered on Pt-buffered Silicon Substrates,TM277
  10. Synthesis, Phase Transformation and Photo-sensitivity of In2Se3 Nanowires,TB383
  11. Measurement the Ion Density and Energy of Plasma in Magnetron Sputtering Filming,TG174.4
  12. The Ion Beam Preparation and Characterization of Hafnium-based Gate Dielectric Doped Tantalum,TB383.2
  13. Preparation and Characterization of SiC Films and Nanowires,TB383.2
  14. Study on the Performance of Auxiliary Anode in the High-energy Ion Beam Sputtering Coating Machine,TG174.4
  15. Synthesis and Characterization of BiFeO3/La0.7Sr0.3Mo3 Multi-layer Film,TB383.2
  16. Magnetic Field Optimization and Erosion Simulation of Circle Planar Magnetron Sputtering Target,TG174.4
  17. Research and Design on the Quality Control Device for the Distribution Systems,TM76
  18. Research on ZnO Film Preparation and Its Property by Radio Frequency Magnetron Sputtering,TN321.5
  19. Novel Composite TCO Transparent Conductive Films,TB383.2
  20. Design and Implementation on Signal Processing Algorithm for Power Quality Monitoring System,TN911.7
  21. Preparation and Properties of Non-hydrogenated Diomand-like Carbon and Non-hydrogenated Si-doped Diomand-like Carbon Films,TB383.2

CLC: > Industrial Technology > Electrotechnical > Independent power supply technology (direct power) > Photocell > Solar cells
© 2012 www.DissertationTopic.Net  Mobile