Queen Mary University of London, School of Physics and Astronomy, Mile End Road, London E1 4NS, United Kingdom.
Phys Rev Lett. 2013 May 24;110(21):216602. doi: 10.1103/PhysRevLett.110.216602. Epub 2013 May 23.
Despite the great interest organic spintronics has recently attracted, there is only a partial understanding of the fundamental physics behind electron spin relaxation in organic semiconductors. Mechanisms based on hyperfine interaction have been demonstrated, but the role of the spin-orbit interaction remains elusive. Here, we report muon spin spectroscopy and time-resolved photoluminescence measurements on two series of molecular semiconductors in which the strength of the spin-orbit interaction has been systematically modified with a targeted chemical substitution of different atoms at a particular molecular site. We find that the spin-orbit interaction is a significant source of electron spin relaxation in these materials.
尽管有机自旋电子学最近引起了极大的兴趣，但人们对有机半导体中电子自旋弛豫的基础物理只有部分理解。基于超精细相互作用的机制已经得到了证明，但自旋轨道相互作用的作用仍然难以捉摸。在这里，我们报告了在两个系列的分子半导体上的μ子自旋光谱和时间分辨光致发光测量，其中自旋轨道相互作用的强度通过在特定分子位置用不同原子的靶向化学取代来系统地修饰。我们发现，自旋轨道相互作用是这些材料中电子自旋弛豫的重要来源。
