Osterbacka R, An CP, Jiang XM, Vardeny ZV
Physics Department, University of Utah, Salt Lake City, UT 84112, USA.
Science. 2000 Feb 4;287(5454):839-42. doi: 10.1126/science.287.5454.839.
Several spectroscopic methods were applied to study the characteristic properties of the electronic excitations in thin films of regioregular and regiorandom polythiophene polymers. In the regioregular polymers, which form two-dimensional lamellar structures, increased interchain coupling strongly influences the traditional one-dimensional electronic properties of the polymer chains. The photogenerated charge excitations (polarons) show two-dimensional delocalization that results in a relatively small polaronic energy, multiple absorption bands in the gap where the lowest energy band becomes dominant, and associated infrared active vibrations with reverse absorption bands caused by electron-vibration interferences. The relatively weak absorption bands of the delocalized polaron in the visible and near-infrared spectral ranges may help to achieve laser action in nanocrystalline polymer devices using current injection.
采用了几种光谱方法来研究区域规整和区域无规聚噻吩聚合物薄膜中电子激发的特性。在形成二维层状结构的区域规整聚合物中，链间耦合的增强强烈影响聚合物链的传统一维电子性质。光生电荷激发（极化子）表现出二维离域，这导致极化子能量相对较小、能隙中出现多个吸收带且最低能量带占主导，以及由电子 - 振动干扰引起的具有反向吸收带的相关红外活性振动。离域极化子在可见光和近红外光谱范围内相对较弱的吸收带可能有助于利用电流注入在纳米晶聚合物器件中实现激光作用。
