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

9906282 Wittmershaus这个NSF-GOALI提案为宾夕法尼亚州立大学伊利-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的主要目的是使用由Molecular Probes Inc.生产的TransFluoSpheres荧光微球和染料。在发光太阳能集中器（LSC），并评估其在转换太阳光为电能的性能。 LSC是一种高荧光材料的薄平板，它使用全内反射将光集中在其边缘，在那里它被半导体太阳能电池材料转换为电能。 LSC的主要优势在于其成本。 它作为一种廉价的、无方向性的光收集器，将其吸收的75%的光子聚焦到一个非常小的昂贵的半导体材料区域。与传统的单染料LSC相比，用多染料网络制成的LSC将吸收至少四倍于太阳的光子。 构建染料网络以优化染料之间的共振激发能量转移，最小化与发射的再吸收相关的损失。 在染料上产生的激发在它们之间跳跃，直到它们最终在最低能级的染料分子上，然后染料分子在LSC内发射这种能量作为荧光。 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。 这些球体直径为40 nm，含有六种或更多种类型的染料，导致吸收光谱覆盖了350至720 nm的整个可见光区域。 他们还将设计和测试由含有适当相对浓度的多种染料的塑料薄膜组成的LSC，以创建像球体一样的高效激发能量转移网络。他们将把球体和多种染料薄膜纳入LSC的新设计中。 将使用太阳照明测量LSC边缘的光浓度，并将其与单染料LSC的公开数据进行比较。 球体和薄膜的光学性质也将进一步表征和建模。 将评估在地面光和温度条件下降解对材料寿命的限制。这项工作将是LSC设计策略的重大变化，并导致其光收集的预期四倍改善，最终降低每千瓦的成本！ 他们将增加他们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量转移网络的可行性。 这将导致更好地评估在其他光学应用中使用这些材料的潜力，如激光，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.***