Needle-shaped 3D dye-sensitized solar cells using anodized Ti wire and Pt nanoparticle/carbon fiber electrodes

Needle-shaped dye-sensitized solar cells are developed using anodized Ti wire and carbon fiber with Pt nanoparticle. The model cell is composed of N719 dye-sensitized TiO2 nanotubes/Ti wire as working electrode, Pt nanoparticle/carbon fiber as a counter electrode and l(-)/l(3)(-) electrolyte encased in a capillary glass tube with internal diameter of 1.0 mm and 40 mm in length. The as-prepared DSSC looks like a needle leaf of pine tree. The energy conversion efficiency is 2.21% which can be up to 3.07% after TiCl4 post-treatment of photoanodes. In addition, higher current and output power can be obtained by parallel connection. Pt nanoparticle/carbon fiber is firstly used as counter electrode and the cyclic voltammetries investigation show that Pt nanoparticle/carbon fiber possess higher catalytic activity than Pt wire. Such type DSSC is TCO free and may be capable of achieving a long distance transport of photocurrent and harvesting all light from any direction in surroundings to generate electricity. It has been demonstrated that needle-shaped structure may be a good choice for a solar cell. (C) 2012 Elsevier B.V. All rights reserved.