Shining a new light on molecular biexcitonic processes: novel molecules and DNA origami

揭示分子双激子过程的新亮点：新型分子和 DNA 折纸

• 批准号: RGPIN-2021-03865
• 负责人: Stevens, Amy
• 金额: $ 2.11万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748107
• 关键词: Shining; new; light; molecular; biexcitonic

In the fight against climate change, renewable energy is our strongest ally. Solar energy is an abundant natural resource, especially in Saskatchewan, where we receive an average of 2,264 hours of sunshine per year. A standard industrially-produced solar cell achieves a light-to-electrical output efficiency of only 18-22%, and so much of the light is not absorbed or absorbed only to be dissipated as heat. New materials that rely on biexcitonic energy-transfer processes have the potential to revolutionize the efficiency with which light is captured and transported in solar-harvesting devices. This proposal addresses this transformative opportunity. We will develop a new class of materials, based on azulenes, that maximize solar-radiation capture, as photons from the entire solar spectrum can trigger biexcitonic processes. Excitations, or excitons, created by low-energy photons can combine to produce higher-energy excitons, while each high-energy exciton can split to produce two lower-energy excitons. This singlet-fission (SF) process can increase power-conversion efficiencies as higher electrical currents result for each photon absorbed. However, few molecules fulfill the strict energy-level requirements, and interact with their neighbouring molecules with the appropriate strength, necessary for SF to occur. Our novel approach is to develop a totally new class of azulene-derived molecules in which efficient SF occurs from unusually-high energy levels. We will visualize and quantify the myriad energy-transfer pathways involved in their biexcitonic processes using ultrafast optical spectroscopy techniques. We will also control interactions between molecules by binding them to nano-scale DNA-origami structures, thus constraining their relative positions and precisely tuning their interactions. Through this dual approach, my research group will markedly extend our knowledge of molecules known to exhibit efficient biexcitonic processes and will develop robust, high-performance materials based upon these processes. This research will drastically improve the efficiency of light-harvesting devices and spawn new technologies, such as new medical-imaging modalities, DNA-based drug delivery vehicles, and ultrasensitive environmental detectors. As this approach is based on azulenes, a natural extension is to detect azulene-like defects in graphene, which are a stumbling block in bringing to fruition many graphene-based innovations sought by the electronics industry. The results will help to position Canada as an influential force in renewable energy technologies, and the highly-qualified personnel working on this research will enter the Canadian labour market with transferable next-generation skills in science and technology. Through supportive and proactive mentorship, my graduates will carry forward values of equity, diversity, and inclusivity. Their training will empower them with the knowledge and tools to continue innovating towards a bright future.

在与气候变化的斗争中，可再生能源是我们最强大的盟友。太阳能是一种丰富的自然资源，尤其是在萨斯喀彻温省，我们平均每年获得2,264小时的阳光。标准生产的太阳能电池的光到电源输出效率仅为18-22％，并且如此多的光不会被吸收或吸收，而仅将其作为热量消散。依靠Biexcitonic能量转移工艺的新材料有可能彻底改变在太阳能收获设备中捕获和运输的光的效率。该建议解决了这个变革的机会。我们将基于Azulenes开发一种新的材料，以最大程度地捕获太阳辐射捕获，因为来自整个太阳光谱的光子可以触发Biexcitonic过程。低能光子创建的激发或激发子可以组合以产生更高的能量激子，而每个高能量激子可以分裂以产生两个低能量的激子。随着每种光子吸收的每个光子的较高电流，这种单线拟合（SF）过程可以提高功率转换效率。但是，很少有分子满足严格的能量水平要求，并与其相邻分子具有适当的强度，这是SF发生所必需的。我们的新方法是开发一类全新的叠氮衍生分子，其中有效的SF来自异常高的能量水平。我们将使用超快速光谱技术可视化和量化其Biexcitonic过程中涉及的无数能量转移途径。我们还将通过将分子与纳米级DNA-Origami结构结合来控制它们之间的相互作用，从而限制其相对位置并精确调整其相互作用。通过这种双重方法，我的研究小组将明显扩展我们对已知可以表现出有效的Biexcitonic过程的分子的了解，并将基于这些过程发展出强大的高性能材料。这项研究将大大提高光收发设备和新技术的效率，例如新的医疗成像方式，基于DNA的药物输送车和超敏感的环境探测器。由于这种方法基于叠氮烯，因此自然的扩展是检测石墨烯中的叠氮化缺陷，这是一个绊脚石，可以实现许多电子行业寻求的基于石墨烯的创新。结果将有助于将加拿大定位为可再生能源技术的有影响力的力量，而从事这项研究的高度合格的人员将进入加拿大劳动力市场，并具有科学和技术方面可转移的下一代技能。通过支持和积极主动的指导，我的毕业生将具有公平，多样性和包容性的价值观。他们的培训将通过知识和工具增强他们的能力，以继续创新朝着光明的未来发展。