Increasing Photocurrents in Dye Sensitized Solar Cells with Tantalum-Doped Titanium Oxide Photoanodes Obtained by Laser Ablation
By Ghosh, Rudresh; Hara, Yukihiro; Alibabaei, Leila; Hanson, Kenneth; Rangan, Sylvie; Bartynski, Robert; Meyer, Thomas J. & Lopez, Rene
Published in ACS Applied Materials & Interfaces
2012
Abstract
Laser ablation is employed to produce vertically aligned nanostructured films of undoped and tantalum-doped TiO2 nanoparticles. Dye-sensitized solar cells using the two different materials are compared. Tantalum-doped TiO2 photoanode show 65% increase in photocurrents and around 39% improvement in overall cell efficiency compared to undoped TiO2. Electrochemical impedance spectroscopy, Mott -Schottky analysis and open circuit voltage decay is used to investigate the cause of this improved performance. The enhanced performance is attributed to a combination of increased electron concentration in the semiconductor and a reduced electron recombination rate.