...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, C. Nanomaterials and interfaces >Hot and Relaxed Electron Transfer from the CdSe Core and Core/Shell Nanorods
【24h】

Hot and Relaxed Electron Transfer from the CdSe Core and Core/Shell Nanorods

机译：CdSe核和核/壳纳米棒的热和弛豫电子转移

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Transient absorption spectroscopy has been used to study the rates of electron transfer (ET) from CdSe and CdSe/ZnS core/shell nanorods to adsorbed methyl viologen, MV~(2+). The nanorods are excited with 387 nm light, producing electrons 7700 cm~(-1) above the conduction band edge. Kinetics are measured in particles without adsorbed MV , giving electron cooling and electron—hole recombination times. The kinetics obtained with and without adsorbed MV~(2+) are compared to infer the ET rates. The results indicate that electron cooling occurs on the 0.7—1.8 ps time scale, with the fastest cooling occurring from the highest energy states. Hot electron transfer from the highest energy levels competes with electron cooling, occurring on the 0.5 ps time scale. Bare particle (relaxed) electron transfer occurs on the time scale of less than or about 4 ps. This is faster than biexciton Auger recombination which occurs on the 50 ps time scale. The energy dependence of the ET times can be semiquantitatively understood in terms of penetration of the conduction band wave function past the particle surface and overlap with the adsorbed MV~(2+). In CdSe/ZnS particles, ET to adsorbed MV~(2+) is slower than electron cooling, and hot electron transfer does not occur. For a 1.0 nm thick ZnS shell, the ET from the bottom of the conduction band occurs on a range of time scales, with the fastest component of about 45 ps.
机译：瞬态吸收光谱法已用于研究从CdSe和CdSe / ZnS核/壳纳米棒到吸附的甲基紫精MV〜（2+）的电子转移速率（ET）。纳米棒被387 nm光激发，在导带边缘上方产生电子7700 cm〜（-1）。在没有吸附MV的颗粒中测量动力学，从而获得电子冷却和电子-空穴复合时间。比较有和没有吸附MV〜（2+）时获得的动力学，以推断出ET速率。结果表明，电子冷却发生在0.7-1.8 ps的时间范围内，最快的冷却发生在能量最高的状态。来自最高能级的热电子转移与电子冷却竞争，发生时间为0.5 ps。裸粒子（松弛）电子转移的发生时间小于或等于4 ps。这比在50 ps时标上发生的双激子俄歇重组更快。 ET时间的能量依赖性可以通过传导带波函数穿透粒子表面并与吸附的MV〜（2+）重叠的方式来半定量地理解。在CdSe / ZnS颗粒中，吸附到MV〜（2+）的ET比电子冷却慢，并且不会发生热电子转移。对于1.0 nm厚的ZnS壳，导带底部的ET在一定的时间范围内发生，最快的分量约为45 ps。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号