Preparation And Performance Research Based On Novel Flexible Carbon Counter Electrodes For Dye-Sensitized Solar Cells

Dye-sensitized solar cells(DSSCs) have aroused considerable attention as a representative of the third generation photovoltaic devices because of their high power conversion efficiency(PCE) and low production cost. However, platinum plating FTO glass as counter electrodes of DSSCs are high cost, high quality and fragile. These shortcomings limit the large-scale commercial application of DSSCs. So developing new flexible material of counter electrode and improving the photoelectric conversion efficiency of DSSCs become the focus of current research.Several new flexible 3D carbon nanocomposite materials counter electrodes were prepared by our group, combining favorable flexibility of carbon cloth, good electrical conductivity of carbon nanotubes and high catalytic of graphene quantum dots(NGQDs). Assemble them into dye-sensitized solar cells, through testing, high photoelectric conversion efficiency were obtained. Through a variety of characterization methods, we demonstrate that it is mainly attributed to NGQDs with high catalytic activity. The preparation methods of carbon nanomaterials counter electrodes are simple and effective. The carbon nanocomposite materials counter electrodes are easily prepared and have unique structure, high catalytic activity and electrical conductivity. Large–scale preparation of counter electrodes for dye sensitized solar cell has a good application prospect. The research content is as follows:(1) Applying the method of electrochemical deposition, graphene quantum dots were load to ITO–PEN and carbon cloth. Two new type of flexible composites were prepared under low temperature and high temperature annealing treatment, respectively. Through assembling them into solar cells and testing, the photoelectric conversion efficiency(3.73 % and 6.52 %) were obtained, respectively.(2) Applying the method of screen printing and chemical vapor deposition, two kinds of carbon cloth/carbon nanotube composites counter electrode were prepared. Through comparing photoelectric performance, the photoelectric conversion efficiency of two materials is 6.51 % and 6.66 %, respectively, which can be comparable to the PCE of traditional platinum electrode.(3) Applying the method of electrochemical deposition, NGQDs were load to the electrode of carbon cloth/carbon nanotube composite(made using CVD). After high temperature annealing treatment, a new type of three–dimensional carbon nanomaterials counter electrodes was prepared. Through assembling them into solar cells and testing, high PCE with 7.68 % were obtained. The PCE is 1.14 times of the traditional platinum electrode under the same working conditions.