Authors: C-Y Liao, H.P. Wang, H-P Lin
Affilation: National Cheng Kung University, Taiwan
Pages: 635 - 638
Keywords: DSSC, TiO2, mesoporous TiO2, EXAFS
To enhance solar energy efficiency of a dye-sensitized solar cell (DSSC), high crystallinity mesoporous TiO2 hollow spheres (MHS-TiO2) have been coated on the photoanode. The MHS-TiO2 was prepared by calcination of the Ti(OBu)4 coated mesoporous carbon hollow spheres at temperature of 873 K. Observations by XRD, TEM, FE-SEM and Raman suggest that the MHS-TiO2 is consisted of mainly anatase. The specific absorption edge and band gap of the MHS-TiO2 determined by diffuse reflectance ultraviolet-visible (DR UV-vis) spectroscopy are 200-420 nm and 3.3 eV, respectively. The apparent surface area of the MHS-TiO2 is in the range of 100-150 m2/g with pore sizes of 5-15 nm. By X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), it is found that the MHS-TiO2 possesses Ti-O bond distances of 1.96-1.97 Å and coordination numbers of 3.7-4.2. The current-voltage (I-V) curves of the DSSC utilizing the MHS-TiO2 in the photoanodes has been determined on a solar energy simulator. It is worth to note that the enhancement of the solar energy conversion efficiency (η) of the DSSC with the MHS-TiO2 photoanode is 33%.