Zeng Chen

CdS/CdSe Co-sensitized Solar Cells Based on Hierarchically Structured SnO2/TiO2 Hybrid Films

SnO2 nanosheet-structured films were prepared on a fluorine-doped tin oxide (FTO) substrate using ZnO nanosheet as template. The as-prepared SnO2 nanosheets contained plenty of nano-voids and were generally vertical to the substrate. TiO2 nanoparticles were homogeneously deposited into the intervals between the SnO2 nanosheets to prepare a hierarchically structured SnO2/TiO2 hybrid film. The hybrid films were co-sensitized with CdS and CdSe quantum dots. The sensitized solar cells assembled with the SnO2/TiO2 hybrid film showed much higher photoelectricity conversion efficiency than the cells assembled with pure TiO2 films. The lifetime of photoinduced electron was also investigated through electrochemical impedance spectroscopy, which showed that the SnO2/TiO2 hybrid film electrode is as long as the TiO2 film electrode.

Electrochemical Behavior of Al(III) and Formation of Different Phases Al-Ni Alloys Deposits from LiCl-KCl-AlCl3 Molten Salt

The electrochemical behaviors of Al(III) deposits on Ni substrates were investigated in LiCl-KCl-AlCl3 (2 wt.%) molten salts. Various electrochemical methods, including cyclic voltammetry (CV), square wave voltammetry (SWV), and open circuit chronopotentiometry (OCP) were used to explore the deposition processes of Al(III) on Ni substrates. Five kinds of Al-Ni alloys phase were firstly electrodeposited by the regulation of deposition potential form LiCl-KCl-AlCl3 (2 wt.%) molten salts at 753 K. The formation of Al-Ni alloys, such as AlNi3, Ni5Al3, AlNi, Al3Ni2, and Al3Ni were confirmed by X-ray diffractometer (XRD) and the cross-section morphologies were investigated by scanning electron microscope (SEM). Meanwhile, it was found that the temperature of molten salt was another key parameter for the controlling of alloys phase. No Al-Ni alloys phase other than AlNi3 and Ni5Al3 could be deposited at 703 K.

Aluminum-Doped SnO2 Hollow Microspheres as Photoanode Materials for Dye-Sensitized Solar Cells

Al doped SnO2 microspheres were prepared through hydrothermal method. As-prepared SnO2 microspheres were applied as photoanode materials in dye-sensitized solar cells (DSCs). The properties of the assembled DSCs were significantly improved, especially the open-circuit voltage. The reason for the enhancement was explored through the investigation of dark current curves and electrochemistry impedance spectra. These results showed that the Al doping significantly increased the reaction resistance of recombination reactions and restrained the dark current. The efficient lifetime of photoexcited electrons was also obviously lengthened.

Electrodeposition and low-temperature post-treatment of nanocrystalline SnO 2 films for flexible dye-sensitized solar cells

SnO2 porous films were electrodeposited on Ti substrate using pulse-potential technique. These deposited films were dealt with different post-treatments. The effects of the post treatments were investigated through X-ray diffraction, FE-SEM, and Raman spectra. These investigations showed that crystal nanoporous SnO2 films were obtained through low-temperature post-treatment process. The photoelectric conversion efficiency of the SnO2 film treated with both the water vapour treatment and ultraviolet illumination was improved to be 0.35% which was comparable with the conversion efficiency of the film sintered at 550°C.