Multiple-Dye Fluorescent Microspheres and Films-A New Approach for Luminescent Solar Concentrators

这项NSF-GOALI提案为宾夕法尼亚州立大学贝伦德学院和分子探针公司的科学家之间的跨学科研究合作提供了支持。PI的主要目标是在发光太阳能聚光器（LSCs）中使用分子探针公司生产的TransFluoSpheres荧光微球和染料，并评估它们将阳光转化为电能的性能。LSC是一种由高荧光材料制成的薄平板，它利用全内反射将光线集中在其边缘，然后通过半导体太阳能电池材料将其转换为电能。LSC的主要优势是它的成本。它是一种廉价的、无方向性的区域光收集器，通过将其吸收的75%的光子聚焦到非常小的一块昂贵的半导体材料上。与传统的单染料LSC相比，由多种染料网络制成的LSC吸收的太阳光子至少是其四倍。染料网络的构建是为了优化染料之间的共振激发能量转移，最大限度地减少与发射重吸收相关的损失。在染料上产生的激发在它们之间跳跃，直到它们最终到达最低能级的染料分子，然后在LSC内发出这种能量作为荧光。荧光微球的独特之处在于，通过吸收光在染料中产生的95%的激发被转移到低能级染料分子上。球体直径为40纳米，包含六种或更多类型的染料，其吸收光谱覆盖350至720纳米的整个可见区域。他们还将设计和测试LSCs， LSCs由含有多种染料的塑料薄膜组成，在适当的相对浓度下，形成一个像球体一样有效的激发能量转移网络。他们将把球体和多染料薄膜结合到LSCs的新设计中。LSCs边缘的光浓度将使用太阳光照测量，并与已发表的单染料LSCs数据进行比较。球和薄膜的光学性质也将进一步表征和建模。将评估在陆地光照和温度条件下，由于降解而对材料寿命施加的限制。这项工作将是LSCs设计策略的重大改变，并导致其光收集的预期因素提高四倍，最终降低每千瓦成本！他们将增加对球体光学特性的理解，并确定使用多染料薄膜形成有效激发能转移网络的可行性。这将有助于更好地评估这些材料在其他光学应用（如激光）中的潜力，并可能有助于分子探针改进其荧光生物探针

9906282WittmershausThis NSF-GOALI proposal provides support for an interdisciplinary research collaboration between Penn State Erie-The Behrend College and the scientists of Molecular Probes Inc. The PI's primary objective is to use TransFluoSpheres fluorescent microspheres and dyes manufactured by Molecular Probes Inc. in luminescent solar concentrators (LSCs) and assess their performance in converting sunlight to electricity. A LSC is a thin, flat plate of highly fluorescent material that uses total internal reflection to concentrate light at its edges where it is converted to electricity by semiconductor solar cell material. The main advantage of the LSC is its cost. It acts as a cheap, non-directional, area collector of light by focusing 75% of the photons it absorbs down to a very small area of expensive semiconductor material.A LSC made with multiple-dye networks will absorb at least four times as many of the sun's photons as compared to traditional single-dye LSCs. The dye networks are constructed to optimize resonant excitation energy transfer among the dyes, minimizing losses associated with reabsorption of emission. Excitations created on the dyes hop among themselves until they end up on the lowest energy level dye molecules which then emit this energy as fluorescence within the LSC. The fluorescent microspheres are unique in that 95% of the excitations created in the dyes through the absorption of light are transferred to the low-energy level dye molecules. The spheres are 40-nm in diameter and contain six or more types of dyes resulting in an absorption spectrum that covers the entire visible region from 350 to 720 nm. They will also design and test LSCs composed of a thin-film of plastic containing multiple dyes at the proper relative concentrations to create an efficient excitation energy transfer network like the spheres.They will incorporate the spheres and multiple-dye thin films into new designs for LSCs. Light concentration at the LSCs' edge will be measured using solar illumination and compared with published data for single-dye LSCs. The optical properties of the spheres and thin films will also be further characterized and modeled. Limits on the lifetime of the materials imposed by degradation under terrestrial light and temperature conditions will be assessed.This work will be a significant change in the strategy of designing LSCs and lead to an expected factor of four improvement in their collection of light, ultimately giving a lower cost per kilowatt! They will increase their understanding of the optical characteristics of the spheres and determine the feasibility of using multiple-dye thin films to form efficient excitation energy transfer networks. This will lead to better assessments of the potential for using these materials in other optical applications, such as lasers, and may assist Molecular Probes in improving their fluorescent bioprobes.***