Physics and Applications of Doping in Molecular Semiconductor Films

分子半导体薄膜中掺杂的物理和应用

• 批准号: 1005892
• 负责人: Antoine Kahn
• 金额: $ 36.98万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1005892&HistoricalAwards=false
• 关键词: Physics; Applications; Doping; Molecular; Semiconductor

Technical: This project addresses fundamental issues in organic semiconductor materials; dopant selection, impact of doping on the electrical behavior of molecular films and interfaces, and features of doping particularly relevant to device performance. The approach encompasses: a search for strongly reducing agents of the organometallic 'sandwich' type. Cr- or Fe-based organometallics such as Fe(C5H5)(C6Me6) are predicted to have an ionization energy 200-300 meV smaller than the strongest molecular n-dopant investigated to date. Similarly, strongly oxidizing agents in the transition metal dithiolene family and transition metal oxides will be studied, along with the stability of the dopant vs. diffusion or contamination as a function of operating conditions (temperature, environment). In the second area of research the relative benefits of interface doping vs. interface engineering (electrode modification) in terms of carrier injection will be addressed. The impact of doping on the mobility of carriers in bulk films, and whether the benefit of doping-induced filling deep traps outweighs additional scattering and trapping caused by these impurities will be assessed. Scanning tunneling microscopy/ spectroscopy (STM/STS) will be used to investigate dopants and related potentials with molecular resolution. The third general theme of the research, application of doping to devices, will involve investigation of power conversion efficiencies in organic photovoltaic cells doped on both sides, i.e., p-doped donor and n-doped acceptor layers, to improve carrier extraction, contacts and electron-hole pair separation. The use of transition metal oxide molecules (as dopants) and films (as high work function electrodes) for charge generation layers and key structures of high efficiency, multi-layer stacked devices will also be studied. These activities will involve a multi-technique approach to fully characterize the electronic, chemical and charge transport properties of these materials (ultra-violet, X-ray and inverse photoemission spectroscopy, STM/STS, current- and capacitance-voltage measurements). Collaborations with chemists, device physicists and theoreticians are established, and will be an integral feature of the research approach.Non-technical: The project addresses basic research issues in electronics/photonics materials science with high technological relevance, and will provide important opportunities for student training. The project is expected to improve our understanding and facilitate the generalization of chemical doping in organic devices, with potentially important industrial applications. It will expose students (graduate and undergraduate) to a range of fundamental materials physics and electronic structure problems, as well as to practical device issues, to a variety of experimental techniques, and to different research environments through collaborations in chemistry and theory of electronic structure. Through his participation in outreach programs at Princeton University, short courses given to industry, and involvement in scientific societies, the PI has been and will remain extremely active in the teaching and dissemination of knowledge in the field of organic electronics.

技术：该项目解决有机半导体材料的基本问题；掺杂剂的选择，掺杂对分子膜和界面电行为的影响，以及与器件性能特别相关的掺杂特性。该方法包括：寻找有机金属“三明治”型的强还原剂。预计基于Cr或Fe的有机金属，如Fe(C5H5)（C6Me6）的电离能比迄今为止研究的最强分子n掺杂剂小200-300 meV。同样，过渡金属二硫烯家族和过渡金属氧化物中的强氧化剂将被研究，以及掺杂剂对扩散或污染的稳定性作为操作条件（温度，环境）的函数。在第二个研究领域中，将讨论界面掺杂与界面工程（电极修饰）在载流子注入方面的相对优势。将评估掺杂对体膜中载流子迁移率的影响，以及掺杂诱导填充深阱的好处是否超过这些杂质引起的额外散射和捕获。扫描隧道显微镜/光谱（STM/STS）将用于研究掺杂剂和相关电位的分子分辨率。本研究的第三个主题是掺杂在器件中的应用，将涉及研究有机光伏电池在两侧掺杂的功率转换效率，即p掺杂给体层和n掺杂受体层，以改善载流子提取，接触和电子-空穴对分离。将过渡金属氧化物分子（作为掺杂剂）和薄膜（作为高功函数电极）用于电荷生成层和高效多层堆叠器件的关键结构也将进行研究。这些活动将涉及多种技术方法，以充分表征这些材料的电子、化学和电荷输运特性（紫外线、x射线和逆光电发射光谱、STM/STS、电流和电容电压测量）。与化学家，设备物理学家和理论家的合作已经建立，并将成为研究方法的一个整体特征。非技术：本项目涉及电子/光子材料科学的基础研究问题，具有很高的技术相关性，并将为学生的培训提供重要的机会。该项目有望提高我们的理解，促进有机器件中化学掺杂的推广，具有潜在的重要工业应用。它将使学生（研究生和本科生）接触到一系列基础材料物理和电子结构问题，以及实际设备问题，各种实验技术，以及通过化学和电子结构理论的合作，了解不同的研究环境。通过参与普林斯顿大学的外展项目，为工业界提供短期课程，以及参与科学社团，PI一直并将继续在有机电子学领域的教学和知识传播方面非常活跃。