Mesophase Ordering of TiO2 Film with High Surface Area and Strong Light Harvesting for Dye-Sensitized Solar Cell
S. Agarwala†, M. Kevin†, A. S. W. Wong‡, C. K. N. Peh†, V. Thavasi§ and G. W. Ho*†
Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Institute of Materials Research and Engineering, ASTAR (Agency for Science Technology and Research), 3 Research Link, Singapore 117602, and Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, Engineering Drive 3, University Hall, Singapore 117576
* Corresponding author. Address: Engineering Science, EA 07-37, Department of Electrical and Computer Engineering, 4 Engineering Drive 3, National University of Singapore, Singapore 117576. Tel: (65) 6516 8121. Fax: (65) 67754710. E-mail: firstname.lastname@example.org., †
Department of Electrical and Computer Engineering, National University of Singapore.
Agency for Science Technology and Research.
Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore.
Mesophase ordering and structuring are carried out to attain optimized pore morphology, high crystallinity, stable porous framework, and crack-free mesoporous titanium dioxide (TiO2) films. The pore structure (quasi-hexagonal and lamellar) can be controlled via the concentration of copolymer, resulting in two different types of micellar packing. The calcination temperature is also controlled to ensure a well-crystalline and stable porous framework. Finally, the synthesized mesoporous TiO2 film is modified by adding P25 nanoparticles, which act as scattering centers and function as active binders to prevent formation of microcracks. Adding P25 nanoparticles into mesoporous structure helps to provide strong light-harvesting capability and large surface area for high -efficiency dye-sensitized solar cells (DSSC). The short-circuit photocurrent density (Jsc) of the cell made from mixture of mesoporous TiO2 and P25 nanoparticles displays a higher efficiency of 6.5% compared to the other homogeneous films. A combination of factors such as increased surface area, introduction of light-scattering particles, and