N-Doping of Organic Semiconductor Materials

非技术描述有机半导体是太阳能电池、显示器和传感器等柔性电子产品的有前途的材料。对于许多应用，它们的导电性必须通过增加正电荷(p型)或负电荷(n型)来增加。这一过程被称为分子掺杂。虽然有很多p型有机半导体，但n型有机半导体要罕见得多。此外，它们在环境条件下不太稳定，而且很难控制它们的电导率。推进有机电子领域将需要开发用于n型掺杂的新的电子材料和工艺。该项目的目标是使用催化剂来提高n型掺杂的效率，催化剂是一种可以提高化学反应速度的化合物。研究人员将结合新型有机半导体的合成策略和n型掺杂剂-催化剂对的选择来优化掺杂过程。这项研究将产生一类新的n型有机半导体，具有高性能和增强的稳定性。这项研究还将促进人们对新的n型材料如何影响器件性能的理解。PI的教育目标是培养人们对有机电子材料和设备的积极看法。这将通过扩展到初中生，将课程指导与本科生和研究生研究项目相结合，以及在一家初创公司提供实习机会来培养创业精神来实现。技术描述无机材料的掺杂在半导体行业的进步以及包括医疗诊断、环境科学和国土安全在内的多个领域的进步中发挥了重要作用。对于有机半导体，几种策略已经产生了掺杂的π电子固体，具有极大的增强的光学和电子性能，以及新的材料、物理现象和器件概念。然而，这些进展在很大程度上是由p掺杂(空穴传输)材料实现的，而有用的n掺杂(电子传输)材料在化学可获得性、掺杂效率和环境稳定性方面受到限制。这限制了它们在同时需要p型和n型半导体的设备中的使用。最近，PI和他的同事发现，金属纳米颗粒(例如，Au)可以催化/加速分子掺杂对典型有机半导体的掺杂。本研究项目将：1)阐明催化掺氮过程的机理，并将研究范围扩大到其他类型的催化剂。2)探索其他掺杂剂和半导体，实施迄今未探索的结构设计和合成策略。3)从组成、电子结构、形貌、微结构和光电响应等方面表征了催化和非催化掺杂薄膜的性质。因此，这项研究计划将n掺杂有机物在分子/高分子材料设计、其规模可获得性以及其有用的光电性能方面提高到前所未有的水平。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTIONOrganic semiconductors are promising materials for flexible electronics such as solar cells, displays, and sensors. For many applications, their electrical conductivity must be increased by adding positive (p-type) or negative (n-type) charges. This process is known as molecular doping. While there are many p-type organic semiconductors, n-type organic semiconductors are far rarer. Moreover, they are less stable in ambient conditions, and it can be difficult to control their electrical conductivity. Advancing the field of organic electronics will require development of new electronic materials and processes for n-type doping. The goal of this project is to enhance the efficiency of n-type doping using a catalyst, a compound that enhances the speed of a chemical reaction. The investigator will combine synthetic strategies for new organic semiconductors with selection of n-type dopant-catalyst pairs to optimize the doping process. This research will result in a new class of n-type organic semiconductors with high-performance and enhanced stability. This research will also promote understanding on how the new n-type materials affect device performance. The PI’s educational goal is to foster a positive perception of organic electronic materials and devices. This will be accomplished through outreach to middle and high school students, coupling course instruction to undergraduate and graduate research projects, and providing internship opportunities at a start-up company to foster entrepreneurship.TECHNICAL DESCRIPTIONThe doping of inorganic materials has been instrumental in the progress of the semiconductor industry and advances in numerous fields including medical diagnostics, environmental science, and homeland security. For organic semiconductors, several strategies have yielded doped π-electron solids with greatly enhanced optical and electronic properties as well as novel materials, physical phenomena, and device concepts. However, these advances were largely enabled by p-doped (hole transporting) materials, while useful n-doped (electron-transporting) materials have been limited in chemical accessibility, doping efficiency, and environmental stability. This limits their use in devices where both p-type and n-type semiconductors are required. Recently, the PI and coworkers discovered that metal nanoparticles (e.g., Au) can catalytically assist/accelerate the doping of representative organic semiconductors by molecular dopants. This research project will: 1) Elucidate the mechanism of the catalytic n-doping process and expand the scope to other type of catalysts. 2) Explore other dopants and semiconductors, implementing to date unexplored structural design and synthetic strategies. 3) Characterize catalyzed vs uncatalyzed doped film properties in terms of composition, electronic structure, morphology, microstructure, and opto-electronic response. Thus, this study plans to bring n-doped organics to unprecedented levels in terms of molecular/macromolecular materials designs, their accessibility in scale, and their useful opto-electronic properties.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.