Influence of surface area on charge transport and recombination in dye-sensitized TiO2 solar cells

被引：178

作者：

Zhu, Kai ^{[1
]}

Kopidakis, Nikos ^{[1
]}

Neale, Nathan R. ^{[1
]}

van de Lagemaat, Jao ^{[1
]}

Frank, Arthur J. ^{[1
]}

机构：

[1] Natl Renewable Energy Lab, Golden, CO 80401 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2006年 / 110卷 / 50期

关键词：

D O I：

10.1021/jp065284+

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The dependence of the electron transport and recombination dynamics on the internal surface area of mesoporous nanocrystalline TiO2 films in dye-sensitized solar cells was investigated. The internal surface area was varied by altering the average particle size in the films. The scaling of the photoelectron density and the electron diffusion coefficient at short circuit with internal surface area confirms the results of a recent study (Kopidakis, N.; Neale, N. R.; Zhu, K.; van de Lagemaat, J.; Frank, A. J. Appl. Phys. Lett. 2005, 87, 202106) that transport-limiting traps are located predominately on the surfaces of the particles. The recombination current density was found to increase superlinearly (with an exponent of 1.40 +/- 0.12) with the internal surface area. This result is at odds with the expected linear dependence of the recombination current density on the surface area when only the film thickness is increased. The observed scaling of the recombination current density with surface area is consistent with recombination being transport-limited. Evidence is also presented confirming that photoinjected electrons recombine with redox species in the electrolyte via surface states rather than from the TiO2 conduction band.

引用

页码：25174 / 25180

页数：7

共 45 条

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