CAREER: Local Probes of Electronic Disorder in Organic Semiconductors

技术：该职业奖的研究部分是利用扫描探针技术，在纳米尺度上研究金属表面有机半导体薄膜的无序性。利用超高真空扫描隧道显微镜，结合为软质材料开发的恒流模式隧道光谱的新定量方法，对金属-有机界面的无序起源进行了评估。研究旨在确定原型无序有机物输运态分布的功能形式，以及输运态在界面平面上的空间相关性。将多层膜与单层膜进行比较，以回答界面无序是否与块状无序有显著区别的问题。基础材料的研究有望通过揭示金属-有机界面电荷注入的主要因素，为有机半导体器件的设计能力做出贡献。利用导电原子力显微镜研究厚层有机半导体薄膜中电荷输运性质的空间无序性。非技术：该项目涉及材料科学主题领域的基础研究问题，具有高技术相关性。如果该项目成功，将对能源相关领域的有机半导体的发展产生影响。该项目的研究和教育活动是一体化的。研究生在跨学科的环境中接受训练。新的扫描探针实验将适用于北卡罗莱纳州立大学的高级本科物理实验室。该计划是修改现有的扫描隧道显微镜，使其允许弹道电子发射光谱，并使用改进的仪器来测量学生生长的薄膜中金属-有机界面的注入屏障。此外，将发展计算研究项目，让本科生探索与扫描隧道光谱相关的一维量子力学方面。

Technical: The research component of this CAREER award is to study disorder in thin films of organic semiconductors on metal surfaces at the nanometer scale, using scanning probe techniques. The origin of disorder at metal-organic interfaces is assessed by ultrahigh vacuum scanning tunneling microscopy combined with new quantitative approaches to tunneling spectroscopy in constant current mode that have been explicitly developed for soft materials. The research aims to determine the functional form of the distribution of transport states for prototype disordered organics as well as the spatial correlation between transport states in the plane of the interface. Multilayer films are compared with monolayer films to answer the question of whether interfacial disorder differs significantly from bulk-like disorder. The basic materials research is expected to contribute to organic semiconductor device design capabilities by revealing the major factors governing charge injection at metal-organic interfaces. The research also aims to reveal the spatial disorder in charge transport properties in thick organic semiconductor films by applying conducting atomic force microscopy.Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance. The project, if successful, can have impacts on the advancement of organic semiconductors for energy related applications. The research and education activities of the project are integrated. Graduate students are trained in an interdisciplinary environment. New scanning probe experiments will be adapted for the senior level undergraduate physics labs at the North Carolina State University. The plan is to modify the existing scanning tunnel microscopy to permit ballistic electron emission spectroscopy and to use the modified instrument to measure injection barriers at metal-organic interfaces in films grown by students. In addition, computational research project will be developed to allow undergraduates to explore aspects of one-dimensional quantum mechanics relevant to scanning tunneling spectroscopy.