• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Conference on Ultrafast Phenomena in Semiconductors and Nanostructure Materials; 20080120-23; San Jose,CA(US) >Sub-picosecond polychromatic photoluminescence studies of CdSe and PbSe nanodots
【24h】

Sub-picosecond polychromatic photoluminescence studies of CdSe and PbSe nanodots

机译：CdSe和PbSe纳米点的亚皮秒多色光致发光研究

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

We present our studies of femtosecond photoluminescence of colloidal solutions of CdSe and PbSe nanocrystals, using polychromatic fluorescence upconversion. Ultrafast relaxation processes are observed in both cases upon excitation at 400 nm and 800 nm respectively. Under moderately high excitation densities we studied the formation and dynamics of biexitons and triexcitons in CdSe nanocrystals. Contrary to earlier reports, all results could be understood without invoking the presence of charged particles. The dynamics of single excitons in PbSe nanocrystals is found to be similar to the case of CdSe, despite the high confinement in the former., The early-time spectra are characterized by emission from several low lying excited states. The kinetics point to a fast sequential cascade process between excited states, governed by energy gaps, and indicate the presence of additional dark states. The first direct measurement of the lowest excited states Huang-Rhys factors excludes that strong electron-phonon coupling mediates the intraband relaxation.
机译：我们目前使用多色荧光上转换对CdSe和PbSe纳米晶体的胶体溶液进行飞秒光致发光的研究。在两种情况下，分别在400 nm和800 nm处激发时都观察到超快弛豫过程。在中等高激发密度下，我们研究了CdSe纳米晶体中比西酮和三激子的形成和动力学。与先前的报告相反，无需调用带电粒子即可理解所有结果。尽管前者的局限性很高，但发现PbSe纳米晶体中单激子的动力学与CdSe的情况相似。早期光谱的特征是来自几个低位激发态的发射。动力学指向受能隙控制的激发态之间的快速顺序级联过程，并表明存在其他暗态。最低激发态Huang-Rhys因子的首次直接测量不包括强电子-声子耦合介导带内弛豫。

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