Defect Density-Dependent Electron Injection from Excited-State Ru(II) Tris-Diimine Complexes into Defect-Controlled Oxide Semiconductors
Defect Density-Dependent Electron Injection from Excited-State Ru(II) Tris-Diimine Complexes into Defect-Controlled Oxide Semiconductors
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从激发态 Ru(II) Tris-二亚胺配合物到缺陷控制氧化物半导体的缺陷密度相关电子注入
DOI：
10.1021/acs.jpcc.9b09781
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发表时间：
2019
期刊：
影响因子：
3.7
通讯作者：
Kazuhiko Maeda
中科院分区：
文献类型：
--
作者：
Shunta Nishioka;Yasuomi Yamazaki;Megumi Okazaki;Keita Sekizawa;Go Sahara;Riho Murakoshi;Daiki Saito;Ryo Kuriki;Takayoshi Oshima;Junji Hyodo;Yoshihiro Yamazaki;Osamu Ishitani;Thomas E. Mallouk;Kazuhiko Maeda
由光吸收染料和宽禁带氧化物半导体衬底组成的染料敏化太阳能电池和光催化剂作为太阳能转换的一种手段已被广泛研究。尽管存在于氧化物表面的缺陷对从激发态染料分子到氧化物的电子注入效率有很大的影响，但在任何染料敏化体系中，缺陷对电子注入过程的影响还没有被完全理解。在这项研究中，我们提出了一个系统的评价，使用发射的Ru(II)络合物吸附在具有不同缺陷密度的氧化物衬底(HCa_2Nb_3O_(10)纳米片和非化学计量比的SrTiO_3−δ)上。使用这些氧化物，用时间分辨发射光谱观察到从吸附的Ru(II)络合物中注入电子。结果表明，从激发态Ru(II)配合物向氧化物的电子注入既受氧化物缺陷密度的影响，也受Ru(II)配合物激发态氧化电位(EOX*)的影响。随着氧化层缺陷密度的增加，电子注入明显加快，而随着氧化层电子密度的增加，由于陷阱填充效应，电子注入受到抑制。尽管Ru(II)络合物的Eox*比氧化物的导带边缘电势更正，但当使用缺陷氧化物时，可以识别电子注入到缺陷中。根据缺陷密度、氧化物能级和Ru(II)络合物的Eox值，详细讨论了电子注入事件。总体而言，结果表明，通过改变发光络合染料的Eox*来估计氧化物表面缺陷态的势是可能的。
Dye-sensitized solar cells and photocatalysts that consist of a light-absorbing dye and a wide gap oxide semiconductor substrate have been studied extensively as a means of solar energy conversion. Although defects existing at an oxide surface have a significant impact on the electron injection efficiency from the excited state dye-molecule into the oxide, the effects of defects on the electron injection process have not been fully understood in any dye-sensitized system. In this study, we present a systematic evaluation of electron injection into defects using emissive Ru(II) complexes adsorbed on oxide substrates (HCa2Nb3O10nanosheets and nonstoichiometric SrTiO3−δ), which had different defect densities. Using these oxides, electron injection from adsorbed Ru(II) complexes was observed by time-resolved emission spectroscopy. It was shown that electron injection from the excited state Ru(II) complex into an oxide was influenced by the defect density of the oxide as well as by the excited state oxidation potential (Eox*) of the Ru(II) complex. Electron injection was clearly accelerated with increasing defect density of the oxide, and was inhibited with increasing electron density of the oxide because of a trap-filling effect. Even though theEox* of the Ru(II) complex was more positive than the conduction band edge potential of the oxide, electron injection into defects could be identified when a defective oxide was employed. The electron injection event is discussed in detail, on the basis of the defect density and the energy levels of oxides as well as theEox* values of the Ru(II) complexes. Overall, the results suggest that it is possible to estimate the potential of surface defect states in oxide by changingEox* of an emissive complex dye.
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影响因子：
8.6
作者：
Maeda, Kazuhiko;Eguchi, Miharu;Mallouk, Thomas E.
通讯作者：
Mallouk, Thomas E.
时间相关的单光子计数以及交替记录激发和发射
影响因子：
3.6
作者：
H. Dreeskamp;T. Salthammer;A. Läufer
通讯作者：
A. Läufer
DOI：
10.1002/chin.198347024
发表时间：
1983
期刊：
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影响因子：
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作者：
V. Houlding;M. Graetzel
通讯作者：
M. Graetzel
三(2,2-联吡啶)钌的化学催化歧化反应(2 )
影响因子：
4.6
作者：
J. Nagle;R. C. Young;T. Meyer
通讯作者：
T. Meyer
池田茂：“氧化钛（IV）光催化剂粉末中缺陷位点的定量分析”物理化学化学物理。
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