Rawson Jeff, Angiolillo Paul J, Therien Michael J
Department of Chemistry, Duke University, Durham, NC 27708;
Department of Physics, Saint Joseph's University, Philadelphia, PA 19131
Proc Natl Acad Sci U S A. 2015 Nov 10;112(45):13779-83. doi: 10.1073/pnas.1512318112. Epub 2015 Oct 28.
The electron polaron, a spin-1/2 excitation, is the fundamental negative charge carrier in π-conjugated organic materials. Large polaron spatial dimensions result from weak electron-lattice coupling and thus identify materials with unusually low barriers for the charge transfer reactions that are central to electronic device applications. Here we demonstrate electron polarons in π-conjugated multiporphyrin arrays that feature vast areal delocalization. This finding is evidenced by concurrent optical and electron spin resonance measurements, coupled with electronic structure calculations that suggest atypically small reorganization energies for one-electron reduction of these materials. Because the electron polaron dimension can be linked to key performance metrics in organic photovoltaics, light-emitting diodes, and a host of other devices, these findings identify conjugated materials with exceptional optical, electronic, and spintronic properties.
电子极化子是一种自旋为1/2的激发态，是π共轭有机材料中的基本负电荷载流子。大极化子的空间维度源于弱电子-晶格耦合，因此确定了电荷转移反应势垒异常低的材料，而电荷转移反应是电子器件应用的核心。在这里，我们展示了具有大面积离域特性的π共轭多卟啉阵列中的电子极化子。这一发现通过同时进行的光学和电子自旋共振测量得到了证实，同时电子结构计算表明这些材料单电子还原的重组能异常小。由于电子极化子维度可与有机光伏、发光二极管及许多其他器件的关键性能指标相关联，这些发现确定了具有优异光学、电子和自旋电子特性的共轭材料。
