Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1521025 | Materials Chemistry and Physics | 2016 | 12 Pages |
Abstract
In order to improve the energy conversion efficiency of dye-sensitized solar cells (DSSCs), deposition of anatase titanium dioxide (TiO2) composite thin films as the negative electrode was attempted using constant-current electrophoresis with a colloidal mixture of two types of TiO2 nanoparticles with different sizes and surface properties. The first type was synthesized in the present study and had a size of about 5Â nm; these are referred to as TNPs. The second type was commercially obtained TiO2 nanoparticles (P25) with a size of about 20Â nm. The P25-to-TNP mass ratio was changed during electrophoresis. Because the TNPs were small and the film had a high specific surface area, the film was deposited to minimize the P25-to-TNP mass ratio in the region close to the entrance window of the DSSC. The upper limit of the film thickness was markedly increased compared to deposition in a colloid consisting of one or two kinds of TiO2 nanoparticles, but without a particle size gradient. A method for calculating the P25-to-TNP mass ratio, the gradient of the number average particle size, and the specific surface area of thin films with a particle size gradient was proposed. The harvesting efficiency for incident light was improved over a wide wavelength range, and as a result, the energy conversion efficiency of DSSCs fabricated using these thin films was increased.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Ryo Kawakami, Yuuki Sato, Yasushige Mori, Shinzo Yoshikado,