Modification Of Dye-Sensitised Solar Cells By Carbon Mateirals

This paper main by characterization of the SEM, XRD, XPS, etc and batteryassembly and photoelectricity performance test in order to find a way to improve theDSSCs properties and methods. The main contents and results of this dissertation arelisted as following:In this paper, the preparation process and influence of crystal form by sinteringtemperature was studied though the Sol-Gel preparation nano-TiO₂. The results showthat the water is an important factor that influence of hydrolysis and polycondensationin the system, Ti（OC4H9）4: H2O volume is5: l in the experiment. When the sinteringtemperature450℃, nano-TiO₂is anatase, began to appear anatase to change in rutileat nearly500℃, and basically completed in rutile at700℃. Photoanode sinteringtemperature are determined at450-480℃。When MWCNTs and mixed-acid-treatment MWCNTs and conductive-carbonblack was acted as a counter electrode instead of Pt, and the influence of photoelectricperformance of DSSCs is analyzed. Acid-treatment MWCNTs, acted as counterelectrode, shows high catalytic activity for I-/I3-redox reaction with the cells opencircuit voltage, short circuit current density of0.552V and0.223mA/cm2and thephotoelectric conversion efficiency of4.10%, respectively. Furthermore, its aging rate isonly the Pt counter electrode1/96.The influence of eosin Y dye concentration, sensitization time on the photoelectricperformance of DSSCs is discussed. Optimized sensitization conditions are obtained asfollowing: DSSCs show the highest photoelectrical performance when the dyeconcentration and sensitization time are0.5g/L and30min, respectively.On the basis of the eosin Y-sensitized conditions, further research on conductivecarbon black to connect dye molecules and nano-TiO₂is occurred, and the effect ofdifferent content on the electrical properties of DSSCs is analyzed. The results showedthat DSSCs has best photoelectrical performance when added0.05g of conductivecarbon black. The open circuit voltage increased by about33.9%, and short-circuitcurrent density increased from4.385mA/cm2to7.637mA/cm2.Additionally, the pretreatment MWCNTs with different content has importanteffect in the process of powder coating for photoanode of DSSCs. The results show thatDSSCs have the best performance when the content of0.1wt%MWCNTs withpretreatment of mixed acid and then supercritical CO2treatment. DSSCs open circuitvoltage, short circuit current density and photoelectric conversion efficiency are0.630V5.89mA/cm2and2.45%, respectively.