Enhanced Conversion Efficiency of Dye-Sensitized Solar Cells by Optimization of Photoanode Modification Process

摘要

Surface modification of nanoporous TiO_2 photoanodes was conducted by simple dipping process using aqueous lithium hydroxide (LiOH) solution at varied temperatures and dipping time, and the modified photoanodes were applied to dye-sensitized solar cells (DSSCs). By the optimization of surface-modification temperature (40℃) and time (10 min), DSSC with LiOH-modified TiO_2 layer showed a considerable improvement (8.19%) of about 20% in power conversion efficiency due to an enhanced open circuit voltage and a fill factor, compared to that (6.85%) of reference device with bare TiO_2 layer. The enhancement was mainly attributed to negative shifts of conduction band edges of TiO_2 by LiOH modification.