BRIGE: Bimetallic Plasmonic Nanostructures for Enhanced Light Harvesting in Dye Sensitized Solar Cells

染料敏化太阳能电池（DSSCs）是第三代太阳能设备，在过去十年中迅速出现，作为硅太阳能电池的廉价替代品。虽然低成本的制造工艺使DSSCs非常有前途，但目前器件的光吸收差和固有的低效率（10%）阻碍了成功进入市场。等离子体共振是贵金属纳米结构中传导电子的集体振荡，可以通过调节其几何形状、尺寸和组成来产生强烈的光散射和围绕其表面的电磁近场。金属纳米结构中的等离子体与有机捕光染料耦合可以显著增强染料的光吸收和载流子生成能力。本提案旨在开发一种新的双金属等离子体纳米结构范例，以理解、控制和优化DSSCs中的光捕获。通过结合湿化学合成、受控表面工程、电动力学模拟、器件物理和超快光学，将构建等离子体增强DSSCs，并显著提高其光电流效率。纳米尺度的金属-分子杂化界面在能量转换和能量存储以及光电器件中无处不在。从该项目中获得的信息将为有机/无机界面的光学性质及其如何影响光诱导电子传递过程提供基本的科学见解。拟议的研究工作也将广泛影响未来便携式和固定式能源转换系统的基础设施。高效等离子体DSSCs最终将使廉价的可持续能源系统能够在第三世界国家开发和实施。例如，廉价和可靠的太阳能电力，用作空间加热器的太阳能热转换器，用于偏远村庄的太阳能驱动电机，以及最终将减少温室气体排放的太阳能驱动小型车辆。这些设备将形成一个新的平台，用于一系列光收集设备，包括光电化学电池、光学传感器和太阳能转换系统。扩大代表性不足群体参与工程的活动拟议的研究预计将通过研究生、本科生和K-12学生的积极参与，扩大代表性不足的少数群体（urm）对STEM教育的参与。首席研究员将继续让乌拉尔大学的本科生参与她的研究工作。该项目将在现有课程中开发一个实验室模块，学生将访问URM人口较多的当地大学，并演示用浆果汁制作DSSC。PI还将参与成熟的外展活动，以促进K-12教育，特别是在urm中。PI目前在范德比尔特大学共同领导美国童子军工程探险项目，约67%的高中生参与者是urm。PI目前还参与并将继续为范德比尔特夏季学院（VSA）做出贡献，中学生（50% URM）在那里进行纳米科学实验。VSA的学生在PI的实验室中进行了不同形状和大小的金纳米结构的合成和表征。这项研究是由工程教育和中心部的工程项目扩大参与计划的一部分，即工程项目扩大参与研究启动基金资助的。该研究还通过刺激竞争研究实验计划（EPSCoR）资助，该计划是国际和综合活动办公室的一部分。

Technical Description of the ProjectDye sensitized solar cells (DSSCs) are third generation solar devices that have rapidly emerged in the past decade as an inexpensive alternative to silicon solar cells. While the low cost of fabrication processes make DSSCs highly promising, the poor light absorption and inherent low efficiencies ( 10%) of current devices have hindered successful market entry. Plasmon resonances, which are the collective oscillations of the conduction electrons, in noble metal nanostructures can be engineered by modulating their geometry, dimensions, and composition to generate intense light scattering and electromagnetic near-fields surrounding their surface. Plasmons in metal nanostructures when coupled with light harvesting organic dyes can significantly amplify the dye optical absorption and carrier generation capabilities. This proposal aims to develop a new paradigm of bimetallic plasmonic nanostructures to understand, control, and optimize light harvesting in DSSCs. By combining wet-chemical synthesis, controlled surface engineering, electrodynamics simulations, device physics, and ultrafast optics, plasmon-enhanced DSSCs will be constructed and their photocurrent efficiencies will be significantly enhanced.Non-Technical Explanation of the Project's SignficanceNanoscale metal-molecule hybrid interfaces are ubiquitous in energy conversion and energy storage, as well as in optoelectronic devices. The information learned from this project will provide fundamental scientific insights of the optical properties at the organic/inorganic interface and how that influences optically-induced electron transport processes. The proposed research efforts will also broadly impact the future infrastructure of both portable and stationary energy conversion systems. High efficiency plasmonic DSSCs will ultimately enable inexpensive sustainable energy systems that can be developed and implemented in third-world countries. For example, cheap and reliable solar electricity, solar-thermal convertors for use as space heaters, solar driven motors for niche applications in remote villages, and solar driven small vehicles which will ultimately reduce greenhouse gas emissions. These devices will form a new platform for a range of light harvesting devices including photoelectrochemical cells, optical sensors, and solar-energy-conversion systems. Activities to Broaden Participation of Underrepresented Groups in EngineeringThe proposed research is expected to broaden the participation of underrepresented minorities (URMs) in STEM education through active participation of graduate, undergraduate and K-12 students in the research. The PI will continue to involve URM undergraduates in her research efforts. The project will lead to development of a lab module in an existing class, and students will visit local colleges with high URM population and demonstrate DSSC fabrication with berry juices. The PI will also participate in mature outreach activities to promote K-12 education particularly among URMs. The PI currently co-leads the Boy Scouts of America Engineering Explorers program at Vanderbilt and ~67% of the high school student participants are URMs. The PI also currently participates and will continue to contribute to the Vanderbilt Summer Academy (VSA) where middle school students (50% URM) perform hands on nanoscience experiments. VSA students performed synthesis and characterization of gold nanostructures of variable shapes and sizes in the PI's lab. This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.The research is also funded through the Experimental Program to Stimulate Competitive Research (EPSCoR), which is part of the Office of International and Integrative Activities.