Ultrafast Transient Absorption Measurements of Charge Carrier Dynamics in Single II−VI Nanowires

详细信息    查看全文

• 作者：Christopher R. Carey ; Yanghai Yu ; Masaru Kuno ; Gregory V. Hartland
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：November 5, 2009
• 年：2009
• 卷：113
• 期：44
• 页码：19077-19081
• 全文大小：182K
• 年卷期：v.113,no.44(November 5, 2009)
• ISSN：1932-7455

文摘

Ultrafast transient absorption experiments have been performed on single CdTe and CdSe nanowires with close to diffraction-limited spatial resolution. The traces for the CdTe nanowires show fast picosecond time scale dynamics, which is assigned to charge carrier trapping at surface states. The time constants vary for different nanowires. This is attributed to differences in the energy and/or density of the trap states, presumably due to variations in surface chemistry. The fast decay component is absent in experiments on CdSe nanowires performed under identical conditions, which is consistent with the much higher emission quantum yield of CdSe nanowires compared to CdTe nanowires. Experiments were also performed with the pump and probe positioned at different points along a single CdTe nanowire. The traces show different trapping times, due to spatial variation in the energy and/or density of trap states. These results highlight the importance of single particle measurements for these systems.