• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Novel layered semiconductor quantum structures in new material systems --- III-nitride quantum cascade emitters and detectors, light emission in Fe:ZnSe with quantum cascade laser pumping, theoretical methods with real-time Green's functions, and hyperbolic metamaterials.
【24h】

Novel layered semiconductor quantum structures in new material systems --- III-nitride quantum cascade emitters and detectors, light emission in Fe:ZnSe with quantum cascade laser pumping, theoretical methods with real-time Green's functions, and hyperbolic metamaterials.

机译：新材料系统中的新型分层半导体量子结构---氮化物量子级联发射器和检测器，具有量子级联激光泵浦的Fe：ZnSe发光，具有实时格林函数的理论方法以及双曲线超材料。

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

This dissertation focuses on the theory and the experimental implementation of novel phenomena and devices related to thin layered semiconductor quantum structures, especially in new material systems.;We explore quantum cascade (QC) structures in III-nitride material systems with large conduction band offsets and high longitudinal optical (LO) phonon energy. The first mid-infrared (mid-IR) intersubband (ISB) emission in III-nitride QC structures is demonstrated. The emission is purely transverse magnetic polarized, which verifies its ISB origin. The center of emission at 5 mum is clearly separated from the blackbody radiation, and agrees very well with the design. We also report the first QC detector in metal organic chemical vapor deposition grown III-nitride superlattices. A current responsivity of up to ∼ 100 muA/W and a specific detectivity of up to ∼ 1 x 108 Jones are recorded.;The non-equilibrium Green's function (NEGF) theory is employed for a profound understanding of the subband structure in layered semiconductors. A general model for handling the effects of the interface roughness in thin layered semiconductors is developed within the framework of NEGF. The model predicts an effective grading in the interfaces and an extraordinary fast roughness scattering lifetime (< 0.1 ps), both of which are re-affirmed by the experimentally observed energy shift and unusual broadening in the ISB transitions in III-nitride superlattices. These quantitative results are included in the design of the III-nitride QC emitters and detectors.;The ultra fast ISB scattering lifetime (sub-ps) is detrimental for ultra-short pulsed lasing, thus we explore other routes to this goal. We study light emission from a Fe2+:ZnSe polycrystal with QC laser pumping. Photoluminescence is achieved with its spectral and time-dependent characteristics examined. Effectively, energy stored in the upper state of the QC laser is transferred to the upper manifold of Fe2+:ZnSe with a 106 - 108 times longer lifetime.;Layering of semiconductor structures not only delivers ISB transitions but also enables strong optical anisotropy. And here the mid-IR semiconductor layered metamaterials (hyperbolic metamaterials) are also studied. The metamaterial characteristics with varied layer thicknesses are investigated. We also explore the possibility of inserting a mid-IR QC laser medium into the layered structure aiming at a reduction of the optical loss. The negative refraction characteristics are retained in the composite structure, and smooth carrier transport is achieved.
机译：本文主要研究与薄层半导体量子结构有关的新颖现象和器件的理论和实验实现，特别是在新材料系统中。;我们探索了具有较大导带偏移的III族氮化物材料系统中的量子级联（QC）结构。高纵向光学（LO）声子能量。展示了III型氮化物QC结构中的第一个中红外（mid-IR）子带间（ISB）发射。发射是纯横向磁极化的，从而验证了其ISB起源。 5毫米处的发射中心与黑体辐射明显分离，并且与设计非常吻合。我们还报告了在金属有机化学气相沉积生长的III型氮化物超晶格中的首个QC检测器。记录的电流响应高达〜100μA/ W，比检测率高达〜1 x 108 Jones .;非平衡格林函数（NEGF）理论用于深刻理解层状半导体中的子带结构。在NEGF的框架内，开发了用于处理薄层半导体中界面粗糙度影响的通用模型。该模型预测了界面中的有效渐变以及非凡的快速粗糙度散射寿命（<0.1 ps），这两者均通过实验观察到的III型氮化物超晶格中的能量位移和ISB跃迁中的异常展宽而得到再次证实。这些定量结果包括在III型氮化物QC发射器和检测器的设计中。超快ISB散射寿命（sub-ps）对超短脉冲激光有害，因此我们探索实现此目标的其他途径。我们用QC激光泵浦研究了Fe2 +：ZnSe多晶体的发光。通过检查其光谱和时间相关特性可以实现光致发光。有效地，存储在QC激光器上部状态的能量以长106-108倍的寿命转移到Fe2 +：ZnSe的上部歧管。半导体结构的分层不仅提供了ISB跃迁，而且还实现了强大的光学各向异性。在此还研究了中红外半导体层状超材料（双曲线超材料）。研究了具有不同层厚度的超材料特性。我们还探索了将中红外QC激光介质插入层状结构以降低光学损耗的可能性。负折射特性保留在复合结构中，并实现了平稳的载流子传输。

著录项

  • 作者

    Song, Yu.;

  • 作者单位

    Princeton University.;

  • 授予单位 Princeton University.;
  • 学科 Electrical engineering.;Condensed matter physics.;Applied mathematics.
  • 学位 Ph.D.
  • 年度 2014
  • 页码 125 p.
  • 总页数 125
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 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