Assessment of Hot-Carrier Effects on Charge Separation in Type-II CdS/CdTe Heterostructured Nanorods
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- 作者：Makoto Okano ; Masanori Sakamoto ; Toshiharu Teranishi ; Yoshihiko Kanemitsu
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2014
- 出版时间：September 4, 2014
- 年：2014
- 卷：5
- 期：17
- 页码：2951-2956
- 全文大小：784K
- ISSN：1948-7185
文摘
Charge separation in semiconducting materials is an essential process that determines the efficiency of photovoltaic devices and photocatalysts. Herein, we report the charge-separation dynamics in type-II CdS/CdTe heterostructured nanorods revealed by femtosecond transient-absorption (TA) measurements with a broad-band white-light probe. Under selective excitation of the CdTe segment, bleaching signals at the band gap energy of CdS were clearly observed with a rise component on a subpicosecond time scale, which indicates efficient electron transfer from CdTe to CdS. The pump-energy dependence of the TA dynamics shows that hot electrons rapidly relax to the bottom of the conduction band of CdTe, and then the electrons transfer to the CdS segment.