• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nanotechnology >Modal analysis of resonant and non-resonant optical response in semiconductor nanowire arrays
【24h】

Modal analysis of resonant and non-resonant optical response in semiconductor nanowire arrays

机译：半导体纳米线阵列中的谐振和非谐振光学响应的模态分析

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

Nanowire array solar cells have reached efficiencies where it becomes feasible to talk about creating tandem solar cells in order to achieve even higher efficiencies. An example of such a tandem solar cell could be a nanowire array embedded in a membrane and integrated on top of a Si bottom cell. Such a system, however, requires understanding and control of its interaction with light, especially to make sure that the low energy photons are transmitted to the bottom cell. The dependence of the optical response of a nanowire array on the nanowire length, diameter, array pitch, materials surrounding the nanowires, and absorption coefficient of the nanowire material is very strong and possibly resonant, indicating the complexity of the optical response. In this work, we use an eigenmode-based analysis to reveal underlying physics that gives rise to observed resonant and non-resonant behavior. First, we show that an effective refractive index can be defined at long wavelengths, where only a single mode propagates. Second, we analyze the origin of the resonant reflection when the next optical mode becomes propagating and can be 'trapped' in the array and interact with the fundamental mode. Additionally, we define two simple boundaries for the wavelength range of the resonant response: the resonances can only occur if there is more than 1 propagating mode in the array, and they disappear if the 1st diffracted order is propagating in the top or bottom material. Such resonance effects could be detrimental for tandem solar cells. We thus provide recommendations for tuning the geometry of the array and the nanowire materials in order to push the resonant regime to the absorbing regime of the nanowire, where absorption in the nanowires dampens the resonances. Finally, this work demonstrates the strength of an eigenmode-based analysis of the optical response of periodic nanostructures in terms of simplifying the analysis of a complex system.
机译：纳米线阵列太阳能电池达到了效率，可以谈论创建串联太阳能电池以实现甚至更高的效率。这种串联太阳能电池的一个例子可以是嵌入在膜中并集成在Si底部电池的顶部的纳米线阵列。然而，这种系统需要了解和控制其与光的相互作用，特别是为了确保低能量光子被传输到底部电池。纳米线阵列的光学响应对纳米线的纳米线长度，直径，阵列间距，纳米线的材料的依赖性，以及纳米线材的吸收系数非常坚固且可能谐振，表明光学响应的​​复杂性。在这项工作中，我们使用基于特征模型的分析来揭示潜在的物理学，这些物理学产生了观察到的共振和非共振行​​为。首先，我们表明可以在长波长下定义有效的折射率，其中仅单个模式传播。其次，当下一个光学模式变为传播时，我们分析谐振反射的原点，并且可以在阵列中被“被捕获”并与基本模式交互。另外，我们为谐振响应的波长范围定义了两个简单的边界：只有在阵列中存在超过1个传播模式，才能发生谐振，如果第1次衍射顺序在顶部或底部材料中传播超过1。这种共振效应可能对串联太阳能电池有害。因此，我们提供了用于调整阵列的几何形状和纳米线材料的建议，以便将谐振制度推向纳米线的吸收制度，其中纳米线中的吸收抑制共振。最后，在简化复杂系统的分析方面，这项工作证明了基于终年模特的基于光学响应的​​基于光学响应的​​优点。

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