Otro
Stepped light-induced transient measurements of photocurrent and voltage in dye-sensitized solar cells based on ZnO and ZnO:Ga
Registro en:
Journal of Applied Physics. Melville: Amer Inst Physics, v. 106, n. 6, p. 4, 2009.
0021-8979
10.1063/1.3226073
WOS:000270378100134
WOS000270378100134.pdf
Autor
Goncalves, Agnaldo de Souza
Davolos, Marian Rosaly
Masaki, Naruhiko
Yanagida, Shozo
Mori, Shogo
Nogueira, Ana F.
Resumen
In order to explain the higher short-circuit current (J(sc)) with comparable open-circuit voltage (V(oc)) from dye-sensitized solar cells (DSCs) based on gallium-modified ZnO (ZnO:Ga) porous electrodes, the diffusion coefficient (D) and electron lifetime (tau) in DSCs with and without Ga-modified ZnO were studied by stepped light-induced transient measurements of photocurrent and voltage. In comparison to DSCs based on ZnO electrodes, the ZnO:Ga-based solar cells provided lower D and higher tau values. The results were interpreted according to the transport-limited recombination model, where the Ga modification induced a higher density of intraband charge traps. At matched electron densities, a decrease in V(oc) from DSCs based on ZnO:Ga was observed, suggesting a positive shift of the ZnO:Ga conduction band edge. The higher J(sc) can be explained by the positive shift of the ZnO:Ga conduction band edge in addition to the increased roughness factor of the electrode due to the Ga modification. (C) 2009 American Institute of Physics. [doi:10.1063/1.3226073] Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)