Size-dependent electron injection from excited CdSe quantum dots into TiO2 nanoparticles
Size-dependent electron injection from excited CdSe quantum dots into TiO2 nanoparticles
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DOI：
10.1021/ja070099a
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发表时间：
2007-04-11
影响因子：
15
通讯作者：
Kamat, Prashant V.
中科院分区：
文献类型：
--
作者：
Robel, Istvan;Kuno, Masaru;Kamat, Prashant V.
通过控制颗粒尺寸，可以轻松调节从激发态 CdSe 量子点到 TiO2 纳米颗粒的电子注入。飞秒瞬态吸收研究表明，CdSe 量子点热化 s 态的电子转移速率常数随着颗粒尺寸的减小而增加。两个半导体系统的导带之间的能量差充当正常马库斯区域中电子转移的驱动力。通过将 CdSe 粒径从 7.5 nm 减小到 2.4 nm，颗粒间电子转移速率常数增加了 3 个数量级（从大约 10(7) 到 10(10) s(-1)）。
Electron injection from excited CdSe quantum dots into TiO2 nanoparticles can be easily modulated by controlling the particle size. Femtosecond transient absorption studies indicate that the rate constant for electron transfer from the thermalized s-state of CdSe quantum dots increases with decreasing particle size. The energy difference between the conduction bands of the two semiconductor systems acts as a driving force for the electron transfer in the normal Marcus region. An increase in the interparticle electron transfer rate constant by 3 orders of magnitude (from similar to 10(7) to 10(10) s(-1)) has been achieved by decreasing the CdSe particle diameter from 7.5 to 2.4 nm.