Coherence and recombination dynamics in semiconducting nanostructures

半导体纳米结构中的相干和复合动力学

• 批准号: RGPIN-2018-04848
• 负责人: Leonelli, Richard
• 金额: $ 1.75万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=679587
• 关键词: Coherence; recombination; dynamics; semiconducting; nanostructures

When a semiconductor absorbs a photon, an electron is excited to the conduction band, leaving a hole in the valence band. The Coulomb interaction between electrons and holes results in a bound state, the exciton, which controls to a large extent the optical properties of semiconductors. When the semiconductors are structured on a nanometric scale, the exciton optical response is dramatically altered by quantum confinement, localisation and delocalisation processes, exchange interaction and other many-body effects.******My research program is about probing exciton dynamics in the complex energy landscape associated with nanostructures in order to understand how energy is absorbed and redistributed within a collective excitation picture. This issue, which is arguably amongst one of the most exciting in contemporary condensed-matter physics, involves many-body physics within and beyond the perturbative regime. It is also integral to excitonics, which deals with applications, ranging from efficient light emitters to quantum logical devices, where the specific properties of excitons are exploited.******The main thrust of my activities is directed towards the two following systems:******- Exciton localisation and recombination in InGaN/GaN nanowires.***- Extreme excitons in two-dimensional van der Waals semiconductor heterostructures.******These projects involve materials or systems of high potential technological impact, but where the fundamental processes that control exciton creation, relaxation and recombination are imperfectly, if at all, understood. They thus constitute excellent test beds for strongly correlated electron theories.

当半导体吸收光子时，电子被激发到导带，在价带中留下空穴。电子和空穴之间的库仑相互作用导致束缚态，即激子，它在很大程度上控制着半导体的光学性质。当半导体在纳米尺度上结构化时，激子光学响应通过量子限制、定域和离域过程、交换相互作用和其他多体效应而显著改变。我的研究项目是关于探测与纳米结构相关的复杂能量景观中的激子动力学，以了解能量如何在集体激发图像中被吸收和重新分布。这个问题可以说是当代凝聚态物理学中最令人兴奋的问题之一，它涉及微扰机制内外的多体物理学。它也是激子学不可或缺的一部分，激子学涉及的应用范围从高效的光发射器到量子逻辑器件，其中激子的特定属性被利用。我的主要工作是针对以下两个系统：**-InGaN/GaN纳米线中的激子局域化和复合。二维货车德瓦耳斯半导体异质结构中的极端激子。**这些项目涉及具有高潜在技术影响的材料或系统，但其中控制激子产生、弛豫和复合的基本过程不完全（如果有的话）被理解。因此，它们构成了强关联电子理论的极好的试验台。