Collaborative Research: Modular Design of Cross-Conjugated Organic Semiconductors

爱荷华州立大学的Malika Jeffries-EL由大分子、超分子和纳米化学项目资助，由爱荷华州立大学和北乔治亚学院的科学家组成的团队进行合作研究。该团队正在开发新的有机电子材料，这意味着它们由碳基分子制成，而不是更常用的无机材料，如基于硅或锗的材料。除了它们的相对丰度之外，这些有机材料的制造成本要低得多，并且提供了无机物质所没有的一系列特性。在这个项目中，综合、理论计算和物理测量研究相结合，设计和制造工作的电子设备。这项工作不仅对电子行业产生了广泛的影响，而且还为本科生和研究生提供了跨学科的研究经验，通过创造性的推广工作，培养了对化学的兴趣，目标是所有教育水平的女性和代表性不足的少数民族学生。该项目致力于开发用于有机发光二极管和光伏电池的新型交叉共轭有机半导体。特别是，新的交叉共轭低聚物组成的强效苯并二苯并异恶唑（BBO）部分正在研究中。BBO是一种独特的交叉共轭环体系，既可以通过恶唑环偶联，也可以通过中心苯环偶联，从而产生具有不同性质的物质。该小组正在合成具有垂直共轭轴的材料，因为它们具有空间隔离的前沿分子轨道。这为最低未占据分子轨道（LUMO）或最高已占据分子轨道（HOMO）的半独立调谐提供了一种手段。该方法的好处是交叉共轭平台允许有机会优化材料？S光学和电子特性的特定应用。人们正在制备各种材料，并通过将最有前途的材料结合到工作装置中进行进一步研究。

Malika Jeffries-EL of Iowa State University is funded by the Macromolecular, Supramolecular and Nanochemistry Program for collaborative research involving a team of scientists from both Iowa State and North Georgia College. The team is developing new electronics materials that are organic, meaning they are made from carbon-based molecules rather than the more commonly used inorganic materials, such as those based on silicon or germanium. In addition to their relative abundance, these organic materials have much lower fabrication costs and provide a range of properties not found in the inorganic substances. In this project, a combination of synthesis, theoretical calculations and physical measurement studies are being combined to design and fabricate working electronic devices. This work is having a broad impact not only on the electronics industry, but also by providing an interdisciplinary research experience for both undergraduate and graduate students, which fosters an interest in chemistry through a creative outreach effort targeting female and underrepresented minority students at all educational levels.This project focuses on developing new cross-conjugated organic semiconductors for use in organic light emitting diodes and photovoltaic cells. In particular, novel cross-conjugated oligomers comprised of the robust benzobisoxazole (BBO) moiety are being studied. BBO is used as the electron-deficient building block since it is a unique cross-conjugated ring system that can be coupled either through the oxazole rings or through the central benzene ring, producing substances with different properties. The group is synthesizing materials with perpendicular conjugation axes because they have spatially segregated frontier molecular orbitals. This provides a means for semi-independent tuning of either the lowest unoccupied molecular orbital (LUMO) or highest occupied molecular orbital (HOMO). The benefits of the approach are that the cross-conjugated platform allows for the opportunity to optimize the material?s optical and electronic properties for specific applications. Various materials are being prepared and the most promising ones studied further by incorporation into working devices.