| Title |
Improvement of Charge Transfer Efficiency of Dye-sensitized Solar Cells by Blocking Layer Coatings |
| Authors |
최우진(Choi, Woo-Jin) ; 김광태(Kim, Kwang-Tae) ; 곽동주(Kwak, Dong-Joo) ; 성열문(Sung, Youl-Moon) |
| DOI |
https://doi.org/10.5370/KIEE.2011.60.2.344 |
| Keywords |
Dye-sensitized solar cells ; Blocking layer ; TiO_2 ; RF magnetron sputtering |
| Abstract |
A layer of TiO_2 thin film less than ~200nm in thickness, as a blocking layer, was deposited by 13.56 MHz radio frequency magnetron sputtering method directly onto the anode electrode to be isolated from the electrolyte in dye-sensitized solar cells (DSCs). This is to prevent the electrons from back-transferring from the electrode to the electrolyte (I^-/{I_3}^-). The presented DSCs were fabricated with working electrode of F:SnO_2(FTO) glass coated with blocking TiO_2 layer, dye-attached nanoporous TiO_2 layer, gel electrolyte and counter electrode of Pt-deposited FTO glass. The effects of blocking layer were studied with respect to impedance and conversion efficiency of the cells. The, electrochemical impedances of DSCs using this electrode were R_1: 13.9, R_2: 15.0, R_3: 10.9 and R_h: 82{Ω}. The R_2 impedance related by electron movement from nanoporous TiO_2 to TCO showed lower than that of normal DSCs. The photo-conversion efficiency of prepared DSCs was 5.97% (V_{oc}: 0.75V, J_{sc}: 10.5 mA/cm^2, ff: 0.75) and approximately 1% higher than general DSCs sample. |