Preparation Study Of Low-temperature- Based Dye-sensitized Solar Cells Photoelectrode Materials And Properties

Low-temperature dye-sensitized solar cell,due to wider application range of the substrate,can be used in the substrate of soft plastics,which makes it more suitable for industrial roll-to-roll mass production,when compared with the glass substrate dyesensitized solar cell.In this paper,we synthesized N-doped and N,La co-doped TiO₂ nanocrystals and used them as photoelectrode materials to prepare low-temperaturebased DSSC.The short circuit current is increased by optimizing the property of materials,thus the photoelectric conversion efficiency is increased.N-doped TiO₂ material is synthesized by the sol-gel method with urea as nitrogen source and characterized by SEM,TEM,BET,XRD,DRS and XPS analysis,through which finding that the size of N-doped TiO₂ materials are smaller than that of undoped one;And the form of doping N into TiO₂ samples is substituting O in TiO₂ lattice as well as gap doping directly to connect O in TiO₂ and coexisting.Namely,not only N–Ti–N but also Ti–O–N exists in N-doped TiO₂ sample;Also,finding that the doped nitrogen can promote the formation of anatase phase and suppress rutile phase;Doping N can reduce the bandgap width and improve the defect of wider bandgap of pure TiO₂,thereby,the absorption of visible light is improved.The more amount of nitrogen,the higher the utilization rate of sunlight.We make prepared N-doped TiO₂ sample to lowtemperature DSSC,By measuring the I-V curve,we find that the property of N-doped TiO₂ based cells is obviously better than that of undoped one.When the amount of doped N is 4%,the photoelectric conversion efficiency ? reaches the maximum value of 5.18%,and when compared with the ? of 4.22% for pure TiO₂,the efficiency was increased by 22.7%,the short circuit currentincreased by 22.2%.Based on the above N-doped,we select the most optimized nitrogen amount which keeps unchangeable to prepare N,La co-doped TiO₂ particles,SEM,TEM,BET,XRD,DRS and XPS are used to characterize the samples,we find co-doped sample can realize the synergistic effect of two doped elements,which exhibits higher utilization rate of visible light.Finally,the prepared sample was used as photoelectrode material to assemble low temperature DSSC,which were compared with undoped TiO₂-based cell,La-doped TiO₂-based cell and N-doped TiO₂-based cell,which were 4.02%,4.58% and 4.72% respectively.we find that the photoelectric conversion efficiency of N,La co-doped TiO₂ low-temperature-based DSSC is increased by 32.6%,16.4% and 12.9% respectively,the short circuit current is increased by 32.8%,18.5% and 12.8% respectively.