The Application Of TiO 2 Nanotubes And TiO 2 Microspheres In Quantum Dot Sensitized Solar Cells

Because of its lower cost, relatively simple technology, and a high theoretical efficiency, quantum dot-sensitized solar cells（QDSSCs） has been widely concerned.The major factors restricting the photoelectric conversion efficiency of QDSSCs is stated as follows, wide bandgap semiconductor still need to be improved, the solar spectrum utilization rate of quantum dots sensitizers are still low, the high electron recombination of semiconductor /quantum dot-sensitizer/electrolyte interface. In this paper, the main research of QDSSCs is the impact of photoanode membrane structure on the efficiency of the cells.TiO₂ nanoparticles have large specific surface area, and thus can adsorb enough quantum dots sensitizer, so it is a common QDSSCs anode materials. But TiO₂ nanoparticles have a great many of grain boundaries, electronic needs through a lot of grain boundary to transfer to the external circuit, lead to a slower electron transfer rate in the anodic film, and increases the recombination of carriers. Studies have shown that orderly TiO₂ nanotube arrays can provide a transmission channel through which electronic can transport along the radial fastly, improve electron transfer rate and electron collection efficiency, so as to improve current density. This paper uses anodic oxidation method to prepare one-dimensional orderly structure of TiO₂ nanotube arrays, and apply them to Cd S/Cd Se sensitized solar cells. We have explored the surface and internal structure of the nanotube affect the performance of the cells, finally got the champion photoelectric conversion efficiency of 4.86%.3 to 5 nm TiO₂ quantum dots is synthesized by using solvothermal reaction,TiO₂ quantum dots of cyclohexane scatter liquid is spun on conductive glass, to form a sintering density blocking layer to reduce the electronic recombination of Cd S sensitized solar cells, by optimizing the blocking layer thickness with different concentration of TiO₂ scatter liquid we finaly get a efficiency of 3.66%. The blocking layer can effectively inhibit the dark reaction, reduce the loss of the electron in thetransmission process to increase the electron transfer rate and electronic life, increase the open circuit voltage and short circuit current, thus improve the photoelectric conversion efficiency.We add polar solvent in TiO₂ quantum dots dispersion to form the microspheres particle with size of 100-500 nm. The microsphere is composed of lots of TiO₂ quantum dots, and the surface of these microsphere is density but in nanometer scale is rough. This kind of TiO₂ microspheres blended with TiO₂ nanoparticles can be used as excellent photoanode materials. The sub-micron structure TiO₂ can increase the light scattering, raise the utilization ratio of light absorption; TiO₂ nanoparticles can adsorb enough sensitizer for its high specific surface area, at the same time can improve the connectivity between the microspheres, improve the efficiency of electronic transmission. By adjusting the proportion of the two materials to optimize the photoanode structure we finally got a cell efficiency of 4.12%...