Exploring charge transfer at organic device interfaces

该奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。这项研究的目的是更好地了解有机半导体和金属之间在广泛无序范围内发生的电荷转移。这种电荷转移强烈地影响这种界面的电学性质，这对有机晶体管、发光二极管和光伏器件至关重要。该方法是在三种技术上最相关的材料系统上进行三种类型的测量(纳米级电子传输；交流扫描隧道显微镜；和太赫兹时域光谱)。通过结合来自这些互补技术的数据，并与理论合作者合作，将获得关于这些系统中的电荷转移和能量排列的系统知识。这个项目的智力价值在于，它将提高对器件物理的理解，这对于优化和确定有机器件性能的极限是必不可少的。同时，这些问题涉及凝聚态物理学中一些最具挑战性的问题。结合PIS的专业知识，将带来从纳米尺度到宏观以及从DC到THz频率方案的新实验技术。该项目的更广泛影响有三个方面。首先，对这些问题的洞察可能会对有机半导体的商业应用产生直接影响，包括光伏和照明。第二，该项目将支持两名研究生的研究性培训，作为技术劳动力的发展。第三，督导人员将利用外展机会，教育更广泛的社会人士有关有机半导体及相关技术的知识。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The objective of this research is to acquire a better understanding of the charge transfer that takes place at the interfaces between organic semiconductors and metal, over a broad range of disorder in the organic material. This charge transfer strongly affects the electrical properties of such interfaces, which are critical to organic transistors, light-emitting diodes, and photovoltaic devices. The approach is to perform three types of measurements (nanoscale electronic transport; alternating current scanning tunneling microscopy; and terahertz time-domain spectroscopy) on three of the most technologically relevant materials systems. By combining data from these complementary techniques, and working with theorist collaborators, a systematic knowledge of the charge transfer and energetic alignment in these systems will be acquired. The intellectual merit of this project is that it would improve understanding of device physics that is essential for optimization and establishing the limits of organic device performance. Simultaneously, these issues involve some of the most challenging questions in condensed matter physics. Combining the expertise of the PIs will lead to new experimental techniques that span from the nanoscale to the macroscopic and from DC to the THz frequency regime.The broader impacts of this project are threefold. First, the insights into these issues may have direct impact on commercial applications of organic semiconductors, including photovoltaics and lighting. Second, the project will support the research training of two graduate students, as technical workforce development. Third, the PIs will use outreach opportunities to educate the broader community about organic semiconductors and related technologies.