Collaborative Research: NSF-BSF: Understanding Semiconducting Polymers in High-Dielectric-Constant Environments

合作研究：NSF-BSF：了解高介电常数环境中的半导体聚合物

• 批准号: 1905770
• 负责人: Harald Ade
• 金额: $ 37.5万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905770&HistoricalAwards=false
• 关键词: Collaborative; Research; NSF; BSF; Understanding

NON-TECHNICAL SUMMARY:Research into 'plastic' semiconductors has led to materials that can harvest the energy of the sun and convert it into electricity. Yet, current devices made with such semiconducting plastics are complex and require two materials to efficiently convert light into electricity. The current project explores whether eventually this structure could be simplified, possibly yielding devices based on a single material. For this, the effect of the local environment on the electronic and optical properties of the plastic semiconductor will be systematically investigated using model systems to test theories that predict that more efficient devices could be produced by making the local environment of the plastic semiconductor more polar. The fundamental insight achieved in this project will allow to design and produce new plastic semiconductors, improve the efficiency and potentially the stability of plastic-based solar cells, and will likely simplify their production so that they eventually could be printed similar to the way newspapers are printed. These all are factors that would improve the economic viability of plastic semiconductors in a range of applications and, in turn, would contribute to reduced greenhouse gas emission and facilitate implementation of concepts such as zero-energy housing and low-water-intensity farming based on solar cell integrations into greenhouses.TECHNICAL SUMMARY:The planned work aims to significantly advance our fundamental understanding of how high-k environments affect the optoelectronic properties of polymer semiconductors. While the effective dielectric constant, k, of functional polymers can be manipulated via chemical design or the surrounding of the polymer, changes in molecular structure to create a high-k polymers also affect other features, including polarity, molecular packing, phase behavior, and electronic properties. As a consequence, few direct structure/function relations have been experimentally established to date. In this project, various current complications that have hindered the delivery of structure/function interrelations will be circumvented via i) separating the polymer self-assembly during processing from the introduction of the high-k material as much as possible, to allow for a clean before/after comparisons, and ii) pursuing new self-assembly strategies to create molecular hybrid materials and blends. These approaches allow to tune the lengthscales and specific interfacial areas of the self-assembly and, in turn, provide means to disentangle sought-after optoelectronic effects from other factors that might impact optoelectronic properties/materials performance. The knowledge gained during the project will be applied to polymer solar cells, which generally rely on donor:acceptor bulk heterojunctions to achieve efficient exciton splitting. A main goal of the project is to delineate if there is ever a pathway to significantly lower the exciton binding energy (and thus realize efficient exciton splitting in organic solar cells) by modifying k in the vicinity of relevant semiconducting polymer backbones or if one really needs to modify the backbone itself.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要：对“塑料”半导体的研究已经产生了可以收集太阳能量并将其转化为电能的材料。然而，目前用这种半导体塑料制成的设备很复杂，并且需要两种材料才能有效地将光转化为电能。当前的项目探索最终是否可以简化这种结构，从而可能产生基于单一材料的设备。为此，将使用模型系统系统地研究局部环境对塑料半导体的电子和光学特性的影响，以测试预测通过使塑料半导体的局部环境更具极性可以生产更高效的器件的理论。该项目获得的基本见解将允许设计和生产新的塑料半导体，提高塑料太阳能电池的效率和潜在的稳定性，并可能简化其生产，以便最终可以像报纸的印刷方式一样进行印刷。所有这些因素都将提高塑料半导体在一系列应用中的经济可行性，进而有助于减少温室气体排放，并促进零能耗住房和基于太阳能电池集成到温室的低水强度农业等概念的实施。 技术摘要：计划的工作旨在显着增进我们对高 k 环境如何影响塑料半导体的基本了解。 聚合物半导体的光电特性。虽然功能聚合物的有效介电常数 k 可以通过化学设计或聚合物周围环境来控制，但产生高 k 聚合物的分子结构变化也会影响其他特性，包括极性、分子堆积、相行为和电子特性。因此，迄今为止，很少有直接的结构/功能关系通过实验建立。在这个项目中，目前阻碍结构/功能相互关系传递的各种复杂情况将通过以下方式得到规避：i) 尽可能地将加工过程中的聚合物自组装与高 k 材料的引入分开，以便进行清晰的前后比较，以及 ii) 追求新的自组装策略来创建分子杂化材料和共混物。这些方法允许调整自组装的长度尺度和特定界面面积，反过来，提供了将受欢迎的光电效应与可能影响光电特性/材料性能的其他因素分开的方法。该项目期间获得的知识将应用于聚合物太阳能电池，聚合物太阳能电池通常依靠施主：受主本体异质结来实现有效的激子分裂。该项目的主要目标是确定是否有一种途径可以通过修改相关半导体聚合物主链附近的 k 来显着降低激子结合能（从而在有机太阳能电池中实现高效的激子分裂），或者是否确实需要修改主链本身。该奖项反映了 NSF 的法定使命，并通过使用基金会的知识进行评估，被认为值得支持。 优点和更广泛的影响审查标准。