Correlation between Energy and Spatial Distribution of Intragap Trap States in the TiO2 Photoanode of Dye-Sensitized Solar Cells

被引：27

作者：

Wang, Yi ^{[1
]}

Wu, Dapeng ^{[2
,3
]}

Fu, Li-Min ^{[1
]}

Ai, Xi-Cheng ^{[1
]}

Xu, Dongsheng ^{[2
]}

Zhang, Jian-Ping ^{[1
]}

机构：

[1] Renmin Univ China, Dept Chem, Beijing 100872, Peoples R China

[2] Peking Univ, Coll Chem & Mol Engn, Beijing 100871, Peoples R China

[3] Henan Normal Univ, Sch Chem & Chem Engn, Xinxiang 453007, Henan, Peoples R China

来源：

CHEMPHYSCHEM | 2015年 / 16卷 / 10期

关键词：

charge recombination; chemical capacitance; dye-sensitized solar cells; electron transport; sensitizers; NANOSTRUCTURED SEMICONDUCTOR ELECTRODES; NANOCRYSTALLINE TIO2; DIFFUSION-COEFFICIENT; CHARGE-TRANSPORT; BACK-REACTION; INTENSITY DEPENDENCE; AMBIPOLAR DIFFUSION; CYCLIC VOLTAMMETRY; SURFACE-STATE; RECOMBINATION;

D O I：

10.1002/cphc.201500075

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 energy and spatial distribution of intragap trap states of the TiO2 photoanode of dye-sensitized solar cells and their impact on charge recombination were investigated by means of time-resolved charge extraction (TRCE) and transient photo-voltage (TPV). The photoanodes were built from TiO2 nanospheroids with different aspect ratios, and the TRCE results allowed differentiation of two different types of trap states, that is, deep and shallow ones at the surface and in the bulk of the TiO2 particles, respectively. These trap states exhibit distinctly different characteristic energy with only a slight variation in the particle size, as derived from the results of the density of states. Analyses of the size-dependent TPV kinetics revealed that in a moderate photovoltage regime of about 375-625 mV, the dynamics of electron recombination are dominated by shallow trap states in the bulk, which can be well accounted for by the mechanism of multiple-trap-limited charge transport.

引用

页码：2253 / 2259

页数：7

共 74 条

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