期刊
NANO LETTERS
卷 14, 期 4, 页码 1785-1789出版社
AMER CHEMICAL SOC
DOI: 10.1021/nl404307n
关键词
Dye-sensitized solar cell; proton-doped rutile TiO2; electron traps; electron transport; density-functional theory; ambipolar diffusion
类别
资金
- U. S. Department of Energy [DE-FG02-90ER-14162, DE-FG02-11ER-16224]
The cation in the electrolyte of the dye-sensitized solar cell (DSSC) has a profound effect on electron trapping and transport behavior in TiO2 nanocrystalline film; this is one of the important factors that determines the overall efficiency of DSSCs. Here, we present a quantum mechanical investigation on the structures and energetics of proton-induced electron trap states and the thermodynamical barrier heights for the ambipolar diffusion of proton/electron pair using a large cluster model for the computations. Our calculations indicate that protons react with TiO2 to form covalent O-H bonds. This is in contrast to the reaction of Li+ with TiO2, in which case the alkali metal is more accurately described as a simple coordinating cation. The covalent O-H bonding leads both to deeper electron trap states and to significantly higher barriers for the diffusion of carriers. These results are qualitatively consistent with experimental observations, and they extend our understanding of the cation effect in DSSCs at an atomic level of detail.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据