Spin Injection and Relaxation in Organic Semiconductors

技术描述：近年来，有机自旋电子学的研究取得了很大的进展。有机材料的一个重要优点是由于原子序数小，固有的自旋寿命长，导致自旋轨道相互作用较少。最近有报道称有机磁阻响应高达300%。自旋注入和载流子复合在有机发光二极管中的作用也得到了广泛的观察。虽然潜力很大，但仍然存在一些具有挑战性的基本问题，包括自旋注入和自旋翻转的控制机制。界面在有机自旋电子学中起着至关重要的作用。在理解有机自旋电子学的基本过程的知识差距必须弥合，以实现其潜力。该项目的目标是研究自旋注入和弛豫动力学，以了解有机自旋电子学发展的重要基本机制。研究了各种无机衬底与有机材料界面的自旋注入效率，研究了有机半导体薄膜中的自旋弛豫动力学。研究的主要工具是自旋分辨光谱学，并得到其他表面分析技术的支持，包括紫外线和x射线光谱学，逆光谱学，扫描隧道显微镜，原子力显微镜和磁力显微镜。非技术描述：本项目为有机半导体中自旋注入和弛豫的基础材料研究。该项目的成功可以加深对分子系统中自旋相关现象本质的理解，对未来信息技术的有机自旋电子学有潜在的影响。这种影响还来自对具有国际经验和领导能力的快速发展领域的下一代科学家的培训。该项目的主要重点是教育和培训跨学科领域的科学家，包括有机电子材料，表面和界面分析，超快动力学和自旋电子学。该项目的重点是通过罗彻斯特大学女性科学与工程和高中学生的大学预科物理体验等项目增加女性的参与。本项目由电子与光子材料计划（EPM）和凝聚态物理计划（CMP）共同资助。

Technical Description: Research on organic spintronics has gained momentum in the past few years. An important advantage of organic materials is the intrinsically long spin-lifetime because of the small atomic numbers, resulting in less spin-orbit interaction. Strong organic magnetoresistance response as high as 300% has recently been reported. The roles of spin injection and carrier recombination in organic light emitting diodes have also been extensively observed. While the potential is high, there remain challenging fundamental issues, including the mechanisms governing spin injection and spin flip. It is well recognized that interfaces are critical in organic spintronics. The knowledge gap in understanding of the fundamental processes in organic spintronics must be bridged to realize its potential.The goal of this project is to investigate spin injection and relaxation dynamics to understand the underlying fundamental mechanisms important for the development of organic spintronics. The spin injection efficiency is investigated for the interface between various inorganic substrates and organic materials, and the spin relaxation dynamics are studied in organic semiconductor thin films. The primary tool for the investigation is spin-resolved photoemission spectroscopy, supported by other surface analytical techniques including ultraviolet and x-ray photoemission spectroscopy, inverse photoemission spectroscopy, scanning tunneling microscopy, atomic force microscopy, and magnetic force microscopy. Non-Technical Description: The project is on fundamental materials research of spin injection and relaxation in organic semiconductors. Success of the project can enhance the understanding of the nature of spin-related phenomena in molecular system, with potential impact on organic spintronics for future information technologies. The impact also comes from training of the next generation of scientists in a fast advancing field with international experience and leadership. A major focus of the project is educating and training scientists in an interdisciplinary field including organic electronic materials, surface and interface analysis, ultrafast dynamics, and spintronics. A strong emphasis of the program is on increasing participation of women through programs including University of Rochester Women in Science and Engineering and Pre-College Experience in Physics for high-school students.This project is co-funded by the Electronic and Photonic Materials Program (EPM) and the Condensed Matter Physics Program (CMP).