Heinrich-Heine-Universität, Universitätsstr. 1, 40225 Düsseldorf, Germany.
J Phys Chem B. 2010 Jan 21;114(2):714-8. doi: 10.1021/jp908565y.
Polypyrrole films have been prepared by potentiostatic electrochemical polymerization at low temperatures. The cyclic voltammograms and the electronic transport properties of the films are investigated as a function of the polymerization potential. As the potential increases from 520 mV to 1.2 V, the oxidation peak moves to larger voltages, while above 1.2 V, the peak voltage drops again. The film conductivity drops monotonously as the polymerization potential is increased. However, the localization length of the current-carrying states, which characterizes the temperature dependence of the conductivity, correlates with the oxidation peak and shows a minimum for films polymerized at 1.2 V. Furthermore, we show that, with an independent doping step after polymerization, the conductivity of the films can be increased by up to 50%. A maximum conductivity of 1360 S/cm has been observed.
聚吡咯薄膜通过低温下的恒电位电化学聚合制备。作为聚合电势的函数，研究了薄膜的循环伏安图和电子输运特性。随着电势从 520 mV 增加到 1.2 V，氧化峰向更大的电压移动，而超过 1.2 V 时，峰电压再次下降。随着聚合电势的增加，薄膜的电导率单调下降。然而，载流子状态的局域长度（其特征在于电导率对温度的依赖性）与氧化峰相关，并在聚合电势为 1.2 V 时显示出最小值。此外，我们表明，在聚合后进行独立的掺杂步骤，可以将薄膜的电导率提高多达 50%。已经观察到最大电导率为 1360 S/cm。
