SOLAR: Programming the Self-Assembly of Matter for Solar Energy Conversion

有效地收集太阳辐射并将其转化为电能的巨大挑战在于多种长度尺度的工程材料，其结构可以指导能量的流动和电荷的转移和传输，就像在自然发生的光收集系统中一样。由功能性、电活性有机和纳米结构无机材料制备的有机-无机杂化物，在单一复合材料中结合了有机和无机组成块的理想和可调的化学和物理特性，使其成为太阳能技术的有前途的系统。杂化材料既具有有机材料的低成本、大面积加工、高吸光度和量子效率，又具有无机纳米结构的可调光学特性、高载流子电导率和良好的光稳定性。如果混合结构的有机和无机构建块能够在纳米尺度上定位和定向，以调节电荷转移和传输、发射和能量转移的竞争过程，太阳能光伏和发光太阳能聚光器技术将会取得巨大的进步。有机-无机混合材料有望成为超低成本光伏器件的最佳结构之一。目前，混合光伏器件的效率受到吸收红色、高迁移率的有机和无机成分（以匹配太阳光谱并有效收集电荷）的可用性以及具有实现高表面积结的结构的复合材料的限制，但形成良好连接的有机和无机途径。该项目旨在为光伏发电生产显著改进的混合结构。改进的混合材料还可以创造高效率的发光太阳能聚光器，目前在性能上受到材料挑战的限制；目前还没有发现单独的有机和无机材料能够满足广谱收集、接近统一的光致发光效率、低重吸收和良好的光稳定性要求。该项目汇集了化学合成、数学建模和自组织方面的进展，以控制有机和无机构建块的位置和方向，利用化学、材料科学和数学的前沿进展。我们将结合精确控制的1)分子和超分子树状晶系统，以定制不同的结构基序组装；2)可调节大小、形状和组成的纳米晶体，自组装成单组分和多组分超晶格。结构、光学和电探针将与界面几何效应的数学建模相结合，以优化电荷转移和输运、发射和能量转移。研究结果将使有机-无机材料的工程设计成为可能，这些材料将集成在光伏器件和发光太阳能聚光器中。更广泛地说，该研究项目将为具有定制结构的混合材料的自组装开发新的合成方法和数学形式，这对于提供具有优越结构、电子和光学特性的材料非常重要。除了能量收集之外，这些材料在成像、治疗和信息技术方面也有应用。该项目强调工程自组装系统的数学技术，为机器人和生物系统提供了潜在的影响。该项目还将在电子和光学方面探索并建立有机-无机异质结行为的数学模型，这对其在一系列电子和光学器件中的应用至关重要。

The grand challenge in efficiently harvesting and converting solar radiation into electricity lies in engineering materials on multiple length scales with architectures that direct the flow of energy and the transfer and transport of charge, as in naturally occurring light harvesting systems. Organic-inorganic hybrids, prepared from functional, electro-active organic and nanostructured inorganic materials, combine desirable and tunable chemical and physical properties of the constituent organic and inorganic building blocks in a single composite, making them promising systems for solar technologies. Hybrid materials incorporate the low-cost, large-area processing and high absorbance and quantum efficiencies of organic materials with the adjustable optical properties, high carrier conductivities, and good photostability of inorganic nanostructures. Solar photovoltaic and luminescent solar concentrator technologies will be dramatically advanced if the organic and inorganic building blocks of hybrid structures can be positioned and oriented on the nanometer scale to regulate the competitive processes of charge transfer and transport, emission, and energy transfer. Hybrid organic-inorganic materials promise one of the best architectures for ultra-low-cost photovoltaic devices. Currently, the efficiency of hybrid photovoltaic devices is limited by the availability of red-absorbing, high-mobility organic and inorganic components (to match the solar spectrum and efficiently collect charge) and of composites with structures that achieve high surface area junctions, yet form well-connected organic and inorganic pathways. This project aims to produce significantly improved hybrid structures for photovoltaics. Improved hybrid materials may also enable creation of high-efficiency luminescent solar concentrators, which currently are limited in performance by materials challenges; organic and inorganic materials alone have not been found to satisfy the broad-spectrum collection, near-unity photoluminescence efficiency, low re-absorption, and good photostability required. This project brings together advances in chemical synthesis, mathematical modeling, and self-organization to control the position and orientation of organic and inorganic building blocks, exploiting advances at the frontier of chemistry, materials science, and mathematics. We will combine precisely controlled 1) molecular and supramolecular dendrimeric systems tailored to assemble with different structural motifs and 2) nanocrystals of tunable size, shape, and composition that self-assemble into single and multi-component superlattices. Structural, optical, and electrical probes will be combined with mathematical modeling of the effects of interface geometry to optimize charge transfer and transport, emission, and energy transfer. The results will enable engineering of organic-inorganic materials that will be integrated in photovoltaic devices and luminescent solar concentrators.More broadly, the research program will develop new synthetic methods and mathematical formalisms for the self-assembly of hybrid materials with tailored architectures that is important to provide materials with superior structural, electronic, and optical properties. These materials have applications in imaging, therapeutics, and information technology, in addition to energy harvesting. The project's emphasis on mathematical techniques for engineered self-assembling systems offers the potential for impact in robotics and biological systems. The project will also electronically and optically probe and establish mathematical models of the behavior of organic-inorganic heterojunctions key to their application in a range of electronic and optical devices.