Tailored polymers as nucleation templates for the synthesis of fluorescing nanodiamonds

•该项目将为通过聚合物模板工艺控制合成10纳米以下荧光纳米钻石（NDs）建立一个强有力的协议。该聚合物将包含金刚烷型金刚石位点，以促进有效的成核和生长，以及携带杂原子的部分（主要是N，但也有Si， Ge），以实现杂原子空位缺陷（位置，数量）的可控植入。•种子聚合物将应用于高压高温（HPHT）工艺中，使用“活性烃”（异辛烷/四烷）作为小分子模板的碳供应来生长NDs，正如我们用于聚合物模板NDs的初步结果一样。•空缺将通过与当地团体合作进行电子束照射或离子束治疗来引入。退火将在800°C左右的真空或惰性气氛下按照标准程序进行。•我们将首先通过电子显微镜分析获得的NDs，然后通过光学显微镜上的吸收和荧光光谱来研究产生的NV（和SiV， GeV）中心的性质，光致发光量子产率和寿命，以获得有关缺陷浓度的信息。对于最有希望的样品，我们将转向自相关技术，并与量子光学研究所合作研究具有单色中心的样品的磁光效应。聚合物方法允许高局部浓度的模板单元，控制其位置以及精确的缺陷合并。与小分子模板相比，NDs的收率和质量将得到极大的提高。这个项目的具体目标是，越来越复杂：1。制备（杂）金刚烷基单体及其聚合体，聚合具有明确的单模态和窄摩尔质量分布的种子大分子以及各种含N， Si和Ge的金刚烷基单体，为HPHT工艺提供理想的成核位点。2. 高荧光和稳定的具有多色中心的nd的生产，将控制数量的氮杂、硅和锗金刚烷基加入到聚合物模板中，以引导杂原子空位中心。对于NV中心，我们将研究是否可以通过控制电子束加速电压和退火温度来控制NV中心（NV0或NV-）的性质。3. 分别用氮杂烷、硅烷或锗金刚烷或衍生物产生具有单色中心官能团的小nd，将使我们能够在每个聚合物模板单元中只加入一个杂原子，最终合成具有单色中心的几纳米范围内的纳米金刚石，这对于量子传感器是重要的。该工艺将成为自下而上合成荧光纳米金刚石的新金标准。

• The project will establish a robust protocol for the controlled synthesis of sub-10-nm fluorescing nanodiamonds (NDs) by a polymer templating process. The polymers will comprise adamantane-type diamondoid sites to facilitate efficient nucleation and growth as well as heteroatom-carrying moieties (mainly N but also Si, Ge) to achieve controlled implantation of heteroatom-vacancy defects (location, number). • The seed polymers will be applied in a high pressure high temperature (HPHT) process to grow NDs using carbon supply from “reactive hydrocarbons” (isocetane/tetracosane) as known for small molecular templates and as we used for the preliminary results on polymer templated NDs. • Vacancies will be introduced by electron beam irradiation or ion beam treatment performed in collaboration with local groups. Annealing will be done at temperatures around 800 °C in vacuum or under inert atmosphere in accordance to standard procedures. • We will analyze the obtained NDs first by electron microscopy and then by absorption and fluorescence spectra on an optical microscope to investigate the nature of the produced NV (and SiV, GeV) centers, photoluminescence quantum yield and lifetime to gain information about the concentration of defects. For the most promising samples, we will turn to autocorrelative techniques and investigate magneto-optical effects on samples with single colour centers in collaboration with the Institute for Quantum Optics. The polymeric approach allows a high local concentration of templating units with control over their location as well as precise incorporation of defects. The yield and quality of the NDs will be strongly improved compared to small molecular templates. The specific goals of this project are, increasing in complexity:1. Preparation of (hetero-)adamantyl monomers and their polymersPolymerization of seed macromolecules with defined monomodal and narrow molar mass distribution and a variety of N, Si, and Ge containing adamantyl monomers will be performed to present ideal nucleation sites for the HPHT process. 2. Production of highly fluorescing and stable NDs with multiple colour centersA controlled amount of aza-, sila- and germaadamantyl will be incorporated into the polymeric templates to steer the heteroatom-vacancy centers. For NV centers we will examine if we can control the nature of the NV center (NV0 or NV-) by controlling the electron-beam acceleration voltage and the annealing temperature. 3. Generation of small NDs with single colour centersEnd group functionalization with aza-, sila-, or germaadamantane or derivatives, respectively, will allow us to incorporate only one heteroatom species per polymeric templating unit to ultimately synthesize nanodiamonds in the range of a few nanometers with single colour centers, which are important as quantum sensors.The process shall be established as a new gold standard for the bottom-up synthesis of fluorescing nanodiamonds.