Improved Performance of Dye-sensitized Solar Cells Based on Nanotubes-nanoparticles Titania Composite Photoelectrodes ?

摘要

A kind of composite titania crystalline photoelectrodes were fabricated with nanoparticles and hydrothermally synthesized titania nanotubes(TNT) in five composite ratio 0:1,1:3,1:1,3:1,1:0 and applied in dye-sensitized solar cells(DSSC).The short-circuit photocurrent(Jsc),open-circuit photovoltage(Voc) and overall conversion efficiency(η ) were tested by photovoltaic measurement under 37.6mW/cm 2 with 1cm 2 photoelectrode active area. For the same film thickness, the performance of DSSCs were enhanced obviously with the composite electrodes compared with those with bare nanoparticle titania.The improvement contributed to more dye absorption as a result of higher BET surface area demonstrated by dye absorption-desorption experiments, the more light scattering and increase of interfacial contact between the nanotube/dye and the electrolyte. Increasing TNT percentage in electrodes resulted in a persistent growth of dye amount while a sharp increase to a peak and then smooth decrease of Jsc and η . The optimized composite ratio was 1:1 with which the DSSC had highest overall conversion efficiency of 8.22% among all photoelectrodes.