Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany.
Phys Rev Lett. 2011 May 27;106(21):216402. doi: 10.1103/PhysRevLett.106.216402. Epub 2011 May 25.
We use the Kelvin probe method to study the energy-level alignment of four conjugated polymers deposited on various electrodes. Band bending is observed in all polymers when the substrate work function exceeds critical values. Through modeling, we show that the band bending is explained by charge transfer from the electrodes into a small density of states that extends several hundred meV into the band gap. The energetic spread of these states is correlated with charge-carrier mobilities, suggesting that the same states also govern charge transport in the bulk of these polymers.
我们使用 Kelvin 探针方法研究了沉积在各种电极上的四种共轭聚合物的能级排列。当基底功函数超过临界值时，所有聚合物中都观察到能带弯曲。通过建模，我们表明，能带弯曲是由电极中的电荷转移到延伸到能带隙数百毫电子伏特的小态密度引起的。这些态的能量扩展与电荷载流子迁移率相关，表明相同的态也控制着这些聚合物体相中的电荷输运。
