A Study on Radiative Transfer in a TiO2 Photoelectrode for Improvement of Dye-Sensitized Solar Cell Performance

Abstract

Nanoporous TiO2 photoelectrodes of dye-sensitized solar cells (DSSCs) were fabricated from various sized TiO2 particles and the electrical performance was investigated. We found that the cell that made from double-layered photoelectrode, the first layer composed of 21 nm TiO2 particles, and the second layer composed of 7 nm TiO2 particles, can give high performance nearly equal to well-establish cells that have the photoelectrode combined with a scattering layer. To clarify the effects of radiative transfer on cell performance, numerical simulation of the radiative transfer through TiO2 photoelectrodes was carried out. The results revealed that while the light absorption within the photoelectrode is important for improvement of the cell performance, local light absorption within the photoelectrode is also essential. Higher light absorption in the deep photoelectrode region close to the electrolyte layer effectively improves the cell performance, because in this region the electron carriers can easily transfer the electrons from the counter electrode to the photoelectrode.