• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Third order nonlinearity of semiconductor quantum dots composites and optical simulations.
【24h】

Third order nonlinearity of semiconductor quantum dots composites and optical simulations.

机译：半导体量子点复合材料的三阶非线性和光学模拟。

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

Multiphoton processes are emerging as a significant class of phenomena. Accelerated growth in nanotechnology has led to new materials with unique physical and optical properties that have never been observed before. These developments have given rise to potential new applications and devices with physical properties that can far exceed those of traditional materials/systems. And we investigated multi-photon and multi-pulse train processes. First, we investigate novel materials with large third order nonlinearity consisting of semiconductor quantum dots in organic materials. We show that semiconductor quantum dots in an organic host matrix lead to significant enhancement of two-photon absorption. We developed a new synthesis method, and obtained CdS quantum dots using a surfactant as capping agent (decylamine). Historically, the formation of colloidal quantum dot preparation was sufficient for their use. However, for use as absorbers and other devices, the technology must be extended to the formation of thin films of these materials. Therefore we made the first, to our knowledge, optically transparent thin films of colloidal semiconductor quantum dots in reversed micelle structure using polystyrene matrixes. This advancement in material processing is a key enabling tool, which may lead to a new era by providing nanosturctured composite materials with large third-order optical nonlinearity. The beta value of CdS we obtained is 788cm/GW, and this TPA coefficient is almost two orders of magnitude greater than that for bulk CdS. The thin film preparation method is very general and can be adapted to other kinds of semiconductor quantum dot material. We also used our technique for CdSe QD capped with reverse micelle, and we observe the beta value of 304cm/GW.; Second, we used numerical technique, previously developed by Professor Potasek, to investigate hybrid two-photon processes and multi-pulse trains. Many of the chromophores with large two-photon absorption are hybrid materials in which the two-photon absorption is coupled to an excited state absorption. This coupling makes the detailed analysis of the photophysics much more complex. Professor Potasek's numerical method agrees very well with published results. We also examined the details of the carrier dynamics for femtosecond pulses, which also are also in agreement with experimental results.
机译：多光子过程正在作为一种重要的现象出现。纳米技术的加速发展导致了具有独特物理和光学特性的新材料，这是前所未有的。这些发展带来了潜在的新应用和设备，这些应用和设备的物理性能可以远远超过传统材料/系统。并且我们研究了多光子和多脉冲训练过程。首先，我们研究具有大三阶非线性的新型材料，该材料由有机材料中的半导体量子点组成。我们表明，有机基质中的半导体量子点导致双光子吸收的显着增强。我们开发了一种新的合成方法，并使用表面活性剂作为封端剂（癸胺）获得了CdS量子点。从历史上看，胶体量子点制剂的形成足以用于其用途。然而，对于用作吸收体和其他装置，该技术必须扩展到这些材料的薄膜的形成。因此，据我们所知，我们首先使用聚苯乙烯基质以反胶束结构制备了胶体半导体量子点的光学透明薄膜。材料加工的这一进步是关键的实现工具，通过提供具有大的三阶光学非线性的纳米结构复合材料，可以引领新时代。我们获得的CdS的beta值为788cm / GW，并且该TPA系数几乎比批量CdS的TPA系数大两个数量级。薄膜的制备方法非常通用，可以适用于其他种类的半导体量子点材料。我们还用我们的技术对带有反胶束的CdSe QD进行了封盖，我们观察到β值为304cm / GW。其次，我们使用以前由Potasek教授开发的数值技术来研究混合双光子过程和多脉冲序列。具有大的双光子吸收的许多生色团是杂化材料，其中双光子吸收耦合到激发态吸收。这种耦合使光物理的详细分析更加复杂。 Potasek教授的数值方法与已发表的结果非常吻合。我们还检查了飞秒脉冲的载流子动力学细节，这也与实验结果一致。

著录项

  • 作者

    Gao, Yongwang.;

  • 作者单位

    City University of New York.;

  • 授予单位 City University of New York.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 160 p.
  • 总页数 160
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 无线电电子学、电信技术;
  • 关键词

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