Ultra-high aspect ratio titania nanoflakes for dye-sensitized solar cells

Micron sized titania flakes with thickness about 40 nm were used in the titania pastes to assemble dye-sensitized solar cells (DSSCs). Using the same deposition method, better particle dispersion of titania flakes resulted in well bonded and integral films comparing to cracking of Degussa P25 nanoparticle films during the evaporation and sintering processes. There are two features of titania flakes which leads to improved conversion efficiency of DSSC: (1) Higher and stronger adsorption of N-719 dyes due to high specific surface area (2) Stronger light scattering of visible light spectrum because of micron scale wide in two dimensions of the flakes. The thickness of the conducting TiCh was critical to the IV characteristics of DSSC such as the short-circuit current density (I-sc) and open-circuit voltage (Voc). Under the same thick ness basis, calcined titania flakes provided 5 times higher efficiency than the photoelectrodes consisted of Degussa P25 nanoparticles (7.4% vs. 1.2%). (C) 2017 Elsevier B.V. All rights reserved.