CAREER: Engineering Arrays of Organic Light Harvesting Crystals from Solution

廉价的清洁、可再生能源，以扩大美国的能源组合，是当今社会最迫切的需求之一。用溶液处理的有机半导体代替传统的硅有望降低制造成本，并显著提高太阳能电池板的生产能力。这项教师早期职业发展（Career）计划将支持基础研究，解决有机半导体晶体阵列的持续制造问题，以最大限度地吸收阳光和发电。在溶液沉积过程中，可以引导有机半导体晶体形成和生长的薄支架将直接集成到太阳能电池板中。作为一种控制固相结晶的通用策略，本研究的发现将在从一次性传感器到制药制造的广泛科学学科中促进科学进步和促进国家繁荣。通过让学生参与新兴的可再生能源技术，该项目将成为促进K-12学生和女性长期留在科学和工程领域的平台。在纳米孔支架内限制晶体是选择特定晶体取向和多晶型的有力策略，有助于对关键核尺寸和晶体生长机制的基本理解。本研究项目努力将成核事件限制在纳米级环境中，但允许随后的晶体生长在支架之上不受限制地进行。在这样做时，将保留对晶体取向和结构的控制，同时显着增加可访问的晶体表面积。通过系统地改变溶质-溶剂相互作用、溶质-底物相互作用和加工条件，分子参数与原子核的取向、密度和结构之间的关系将被揭示。这些知识将用于建立设计原则，以实现所需的结晶结果。例如，对原子核方向的控制将首次实现垂直有机半导体晶体阵列，其中堆栈方向与溶液处理有机太阳能电池中的电荷输运方向对齐。这一研究策略将与连续加工方法相兼容，与大多数最先进的有机太阳能电池中用于沉积活性层的传统批量旋转涂层相比，将降低制造成本。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Inexpensive sources of clean, renewable energy to expand the US energy portfolio are among the most urgent needs of today's society. Substituting conventional silicon with solution-processed organic semiconductors promises to drive down manufacturing costs and significantly increase the production capacity of solar panels. This Faculty Early Career Development (CAREER) Program grant will support fundamental research addressing the continuous manufacturing of organic semiconductor crystal arrays optimized for maximum sunlight absorption and electricity generation. Thin scaffolds that can guide organic semiconductor crystal formation and growth during deposition from solution will be incorporated directly into solar panels. As a generalizable strategy to control solution-phase crystallization, the findings from this research will promote the progress of science and advance the national prosperity in a broad range of scientific disciplines, from disposable sensors to pharmaceutical manufacturing. By engaging students in emerging renewable energy technologies, this project will serve as a platform to promote long-term retention of K-12 students and women in science and engineering. Confinement of crystals within nanoporous scaffolds is a powerful strategy to select for specific crystal orientations and polymorphs and has contributed to a fundamental understanding of critical nucleus sizes and crystal growth mechanisms. This research project endeavors to restrict nucleation events to nanoscale environments but allow subsequent crystal growth to proceed unconfined above the scaffolds. In doing so, control over the crystal orientation and structure will be retained while significantly increasing the accessible crystal surface area. By systematically varying solute-solvent interactions, solute-substrate interactions, and processing conditions, relationships between molecular parameters and the orientation, density and structure of nuclei will be uncovered. Such knowledge will be used to establish design principles to achieve desired crystallization outcomes. For example, control over the orientation of nuclei will enable the first realization of vertical organic semiconductor crystal arrays in which the stack direction is aligned with the charge transport direction in solution-processed organic solar cells. This research strategy will be compatible with continuous processing methods that will drive down manufacturing costs compared to conventional batch spin coating used to deposit active layers in the majority of the state-of-the-art organic solar cells.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.