Premium
Ultrathin SnO 2 Scaffolds for TiO 2 ‐Based Heterojunction Photoanodes in Dye‐Sensitized Solar Cells: Oriented Charge Transport and Improved Light Scattering
Author(s) -
Yang Shuang,
Hou Yu,
Xing Jun,
Zhang Bo,
Tian Feng,
Yang Xiao Hua,
Yang Hua Gui
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201300524
Subject(s) - materials science , heterojunction , nanosheet , optoelectronics , dye sensitized solar cell , light scattering , nanotechnology , scattering , charge carrier , optics , electrode , chemistry , electrolyte , physics
In this paper, band‐structure matching strategy of a TiO 2 ‐based heterojunction within which electrons can be collected from TiO 2 nanoparticles and transported rapidly in the bulk structure is reported. On the basis of the band‐structure analysis of different TiO 2 ‐based heterostructures, focus was directed to the SnO 2 nanosheet because of its appropriate band position and high electrical conductivity. Through a systematic investigation of the incorporation of ultrathin SnO 2 nanosheet scaffolds for TiO 2 ‐based photoanodes in dye‐sensitized solar cells (DSCs), we propose an anisotropy “constrained random walk” model to describe the controlled electron transit process. In this system, electrons are transferred orientedly overall, as well as randomly locally, leading to a significant reduction in the charge diffusion route compared to the conventional isotropic “random walk” model. In brief, the 2D ultrathin nanosheets provide rapid transit pathways and improved light‐scattering centers, which can ensure a sufficient amount of dye loading and slow recombination. An overall light‐to‐electricity conversion efficiency as high as 8.25 % is achieved by embedding the appropriate amount of SnO 2 scaffold in a TiO 2 ‐based photoanode.