Photoelectrochemistry of Composite Semiconductor Thin Films. Photosensitization of SnO2/CdS Coupled Nanocrystallites with a Ruthenium Polypyridyl Complex
Photoelectrochemistry of Composite Semiconductor Thin Films. Photosensitization of SnO2/CdS Coupled Nanocrystallites with a Ruthenium Polypyridyl Complex
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DOI：
10.1021/jp970833k
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发表时间：
1997-09
影响因子：
3.3
通讯作者：
Chouhaid Nasr and;S. Hotchandani;W. and;R. Schmehl;P. Kamat
中科院分区：
文献类型：
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作者：
Chouhaid Nasr and;S. Hotchandani;W. and;R. Schmehl;P. Kamat
研究了激发态Ru(II)配合物(即(Ru(Bpy)2(L))2+，其中L=4-(2，2‘-联吡啶-4-基)苯基二膦酸根)对SnO_2和SnO_2/CdS薄膜的电荷注入，以阐明复合半导体体系的有利作用。激发态Ru(II)注入到CdS中的电子迅速转移到SnO2纳米团簇中，从而促进电荷分离。光电化学测量表明，在SnO2/CDS复合体系中，光子对光电流的电荷产生效率得到了提高。用暂态吸收光谱研究了氧化产物Ru(III)的形成和敏化剂的回收。SnO_2/Cd_s/Ru(II)复合体系的背电子转移速率常数比SnO_2/Ru(II)体系的慢2−~3。介绍了复合半导体系统在光化学太阳能电池中的应用前景。
The charge injection from an excited Ru(II) complex (viz., (Ru(bpy)2(L))2+, where L = 4-(2,2‘-bipyrid-4-yl)phenyl diphosphonate) into SnO2 and SnO2/CdS films is investigated to elucidate the beneficial effect of composite semiconductor systems. The electrons injected from excited Ru(II) into CdS are transferred quickly into SnO2 nanoclusters, thus promoting the charge separation. Photoelectrochemical measurements suggest improved photon to photocurrent charge carrier generation efficiency in the SnO2/CdS composite system. The formation of the oxidation product, Ru(III), and the recovery of the sensitizer are investigated using transient absorption spectroscopy. The rate constant for the back electron transfer in the SnO2/CdS/Ru(II) composite system is slower by a factor of 2−3 than the one observed in the SnO2/Ru(II) system. The beneficial aspects of composite semiconductor systems in photochemical solar cells are presented.