RUI: Organic Molecular Crystal Growth in Complex Solvent Environments

大多数现代电子设备都是基于无机半导体，如硅。 然而，对于某些应用，原则上可以通过改变由聚合物或小分子组成的分子半导体来获得显着的成本或性能优势。 可以从分子半导体中受益的技术的例子包括更便宜，更高性能的太阳能电池，更薄，机械柔性的显示器，以及更低成本，更高效率的照明。 先前的研究表明，对于这些应用，分子半导体域的微观结构-包括它们的大小，位置和结晶度-严重影响性能。 在材料研究部固态和材料化学项目的支持下，研究人员正在使用光谱成像和高度受控的生长方法，结合理论和建模，研究技术上重要的宿主中的分子半导体结晶。结果将提高对影响微观结构的因素的基本理解，并最终更好地控制它。该研究将主要由本科生进行。因为研究桥梁物理和化学，学生受益于丰富的经验与教师和其他学生具有不同的学术和预备背景的工作，教育他们成为具有较强的跨学科技能协作解决问题。 越来越复杂的结构和材料组合所需的应用，如掺杂聚合物有机发光二极管，裂变敏化有机光致发光，全有机单晶场效应晶体管，地方严格要求的形态，尺寸，晶体取向，空间定位，和其他生长特性的小分子晶体客人，纳入复杂的主机。 有机分子晶体（OMC）的形成发生在多组分、多相环境中，受到热力学和动力学因素的影响，超越了当前理论提供洞察力的能力，更不用说预测性设计指导了。同样地，用于在复杂基质中制备含OMC的有源层的常规方法（例如物理气相沉积、旋转浇铸等）不适用于本发明。通常不能对驱动结晶的变量提供足够的控制，以实现在这种化学和结构多样的溶液环境中推进基本理解所需的受控观察。这项研究是通过研究小分子有机晶体的形成，通过控制测量涉及模型聚合物，小分子和混合流体相主机，并结合这些研究与理论和建模的紧密集成的程序，使广泛的概括有关的设计规则管理OMC形成解决这些挑战。 其目的是更好地了解潜在的化学，动力学和热力学因素影响成核和技术相关的解决方案矩阵的增长。

Non-technical abstractMost modern electronic devices are based on inorganic semiconductors like silicon. For some applications though, significant cost or performance advantages could in principle be gained by changing to molecular semiconductors, composed of polymers or small molecules. Examples of technologies that could benefit from molecular semiconductors include less expensive, higher performance solar cells, thinner, mechanically flexible displays, and lower cost, higher efficiency lighting. Prior research has shown that for applications such as these, the microscopic structure of the molecular semiconductor domains - including their size, position, and crystallinity - critically affects performance. With support from the Solid State and Materials Chemistry program in the Division of Materials Research, researchers are using spectral imaging and highly controlled growth methods, combined with theory and modeling, to study molecular semiconductor crystallization in technologically important hosts. The outcome will be improved fundamental understanding of the factors affecting microscopic structure, and ultimately of ways to better control it. The research will be conducted primarily by undergraduate students. Because the research bridges physics and chemistry, students are benefitting from a rich experience working with faculty and other students with different academic and preparatory backgrounds, educating them to become collaborative problem-solvers with strong interdisciplinary skills. Technical abstractIncreasingly sophisticated architectures and materials combinations required for applications such as doped polymer organic light-emitting diodes, fission-sensitized organic photovoltaics, all-organic single-crystal field-effect transistors, place stringent demands on the morphology, dimensions, crystallographic orientation, spatial positioning, and other growth characteristics of small-molecule crystalline guests, incorporated within complex hosts. Organic molecular crystal (OMC) formation takes place in multicomponent, multiphasic environments, influenced by both thermodynamic and kinetic factors, surpassing the ability of current theory to provide insight, let alone predictive design guidance. Likewise, conventional methods for preparing OMC-containing active layers in complex matrices (e.g. physical vapor deposition, spin casting, etc.) typically do not afford sufficient control over the variables driving crystallization to enable the kinds of controlled observations needed to advance fundamental understanding in such chemically and structurally diverse solution environments. This research is addressing these challenges by studying small-molecule organic crystal formation through controlled measurements involving model polymeric, small-molecule, and mixed fluid phase hosts, and combining these studies with a closely integrated program of theory and modeling to make broad generalizations about the design rules governing OMC formation. The objective is to better understand the underlying chemical, kinetic, and thermodynamic factors influencing nucleation and growth in technologically-relevant solution matrices.