Correlated PL, Raman and IR nanospectroscopy for studying single-photon emitters in hBN

用于研究 hBN 中单光子发射器的相关 PL、拉曼和红外纳米光谱

• 批准号: 467576442
• 负责人: Dr. Iris Niehues
• 金额: --
• 依托单位: CIC nanoGUNE
• 依托单位国家: 德国
• 项目类别: WBP Fellowship
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/467576442?language=en
• 关键词: Correlated; PL; Raman; IR; nanospectroscopy

This proposed project aims on studying single photon emitters (SPEs) in hexagonal boron nitride (hBN) with the help of near-field techniques providing nanoscale spatial resolution.SPEs are essential for future quantum technologies, where single photons on demand are needed. For future applications, SPEs must fulfill special requirements, e.g., they should be stable at room temperature and tunable in energy. SPEs that fulfill these aspects are color centers in hexagonal boron nitride (hBN), whose characteristics are not fully understood yet. For example, it is expected that strain has a major influence on their emission properties, but the underlying mechanisms are still not understood. Novel insights might be achieved by studying the fundamental SPE properties with a spatial resolution much better than the optical diffraction limit. For that reason, I want to use infrared nanoimaging and nanospectroscopy techniques (s-SNOM and nano-FTIR, respectively) as well as tip-enhanced Raman spectroscopy (TERS) and tip-enhanced photoluminescence spectroscopy (TEPL) to study the interplay between local strain and photoluminescence (PL) of SPEs in hBN with nanoscale spatial resolution. For a most reliable correlation of the complementary information provided by these techniques, the project aims on developing a combined nano-FTIR and TERS setup, allowing, for the first time, for simultaneous measurements of nanoscale-resolved infrared, Raman and PL spectra. It is also planned to perform theses studies after manipulation of the emitters’ optical properties by creating macroscopic strain fields in their vicinity, for example via nanointendation. The findings will help for a better understanding of the influence of strain on the emitters´ origin, activation and transition energy.The proposed research will be carried out in the nanooptics group at CIC nanoGUNE (San Sebastian, Spain), which is led by Rainer Hillenbrand, who pioneered the development and application (e.g. mapping phonon polaritons in hBN) of s-SNOM and nano-FTIR. The group also demonstrated that the nano-FTIR instrumentation is well suited for TERS and TEPL measurements, which so far have been developed in parallel, but separately, to s-SNOM and nano-FTIR.My research is currently located in the field of optomechanics of semiconductors, focusing on the PL and absorption studies of strained 2D materials. Besides, I am studying the phononic properties of these materials via Raman spectroscopy and correlate them with their PL. Recently, I investigated the influence of strain on mono- and bilayers and showed that it can be used to manipulate the optical properties via exciton-phonon coupling. I also worked with SPEs in WSe2 monolayers, which I created deterministically by generating nanoscale strain profiles.I am convinced that my background in optomechanics and SPEs combined with the equipment and expertise at CIC nanoGUNE will lead to a successful implementation of the proposed project.

该项目旨在利用近场技术研究六方氮化硼（hBN）中的单光子发射体（SPE），该技术提供纳米级的空间分辨率。SPE对于未来需要单光子的量子技术至关重要。对于未来的应用，SPE必须满足特殊要求，例如，它们在室温下应该是稳定的并且能量是可调的。满足这些方面的SPE是六方氮化硼（hBN）中的色心，其特性尚未完全了解。例如，预计应变对它们的发射特性有重大影响，但其潜在机制仍不清楚。新的见解可能会实现通过研究的基本SPE性能的空间分辨率比光学衍射极限好得多。出于这个原因，我想使用红外纳米成像和纳米光谱技术（分别为s-SNOM和nano-FTIR）以及尖端增强拉曼光谱（TERS）和尖端增强光致发光光谱（TEPL）来研究具有纳米空间分辨率的hBN中SPE的局部应变和光致发光（PL）之间的相互作用。对于这些技术提供的互补信息的最可靠的相关性，该项目旨在开发一个组合的纳米FTIR和TERS设置，允许，第一次，同时测量纳米尺度分辨红外，拉曼和PL光谱。还计划在通过在其附近创建宏观应变场（例如通过纳米强化）来操纵发射器的光学性质之后进行这些研究。这项研究将在CIC nanoGUNE（西班牙圣塞巴斯蒂安）的纳米光学小组进行，该小组由Rainer Hillenbrand领导，他是s-SNOM和nano-FTIR的开发和应用（例如在hBN中映射声子极化激元）的先驱。该小组还证明了nano-FTIR仪器非常适合TERS和TEPL测量，到目前为止，它们已经与s-SNOM和nano-FTIR平行但独立地开发。我的研究目前位于半导体光力学领域，专注于应变2D材料的PL和吸收研究。此外，我正在通过拉曼光谱研究这些材料的声子性质，并将它们与它们的PL相关联。最近，我研究了应变对单层和双层膜的影响，并表明它可以通过激子-声子耦合来操纵光学性质。我还在WSe 2单层中使用SPE，我通过生成纳米级应变曲线确定性地创建了WSe 2单层。我相信，我在光学机械和SPE方面的背景与CIC nanoGUNE的设备和专业知识相结合，将导致拟议项目的成功实施。