Cavendish Laboratory, University of Cambridge, Cambridge CB3 OHE, United Kingdom.
Phys Rev Lett. 2009 Dec 18;103(25):256803. doi: 10.1103/PhysRevLett.103.256803. Epub 2009 Dec 17.
The microstructure of conjugated polymers is heterogeneous on the length scale of individual polymer chains, but little is known about how this affects their electronic properties. Here we use scanning Kelvin probe microscopy with resolution-enhancing carbon nanotube tips to study charge transport on a 100 nm scale in a chain-extended, semicrystalline conjugated polymer. We show that the disordered grain boundaries between crystalline domains constitute preferential charge trapping sites and lead to variations on a 100 nm scale of the carrier concentration under accumulation conditions.
共轭聚合物的微观结构在单个聚合物链的长度尺度上是不均匀的，但人们对这如何影响它们的电子性质知之甚少。在这里，我们使用具有分辨率增强的碳纳米管尖端的扫描开尔文探针显微镜来研究在链扩展的半结晶共轭聚合物中在 100nm 尺度上的电荷输运。我们表明，在结晶域之间的无序晶界构成了优先的电荷俘获位点，并在积累条件下导致载流子浓度在 100nm 尺度上的变化。
