Ortuño Miguel, Escasain Elisa, Lopez-Elvira Elena, Somoza Andres M, Colchero Jaime, Palacios-Lidon Elisa
Dep. de Física - CIOyN, Universidad de Murcia, E-30100 Murcia, Spain.
Dep. Surfaces and Coatings, Instituto de Ciencia de Materiales de Madrid - CSIC (Campus Cantoblanco), E-28049 Madrid, Spain.
Sci Rep. 2016 Feb 25;6:21647. doi: 10.1038/srep21647.
The surface potential of conducting polymers has been studied with scanning Kelvin probe microscopy. The results show that this technique can become an excellent tool to really 'see' interesting surface charge interaction effects at the nanoscale. The electron glass model, which assumes that charges are localized by the disorder and that interactions between them are relevant, is employed to understand the complex behavior of conducting polymers. At equilibrium, we find surface potential domains with a typical lateral size of 50 nm, basically uncorrelated with the topography and strongly fluctuating in time. These fluctuations are about three times larger than thermal energy. The charge dynamics is characterized by an exponentially broad time distribution. When the conducting polymers are excited with light the surface potential relaxes logarithmically with time, as usually observed in electron glasses. In addition, the relaxation for different illumination times can be scaled within the full aging model.
利用扫描开尔文探针显微镜研究了导电聚合物的表面电势。结果表明，该技术能够成为在纳米尺度上真正“观察”到有趣的表面电荷相互作用效应的出色工具。电子玻璃模型假定电荷因无序而局域化且它们之间的相互作用是相关的，该模型被用于理解导电聚合物的复杂行为。在平衡状态下，我们发现表面电势域的典型横向尺寸为50纳米，基本与形貌无关且随时间强烈波动。这些波动比热能大约大三倍。电荷动力学的特征是具有指数形式的宽泛时间分布。当用光照激发导电聚合物时，表面电势会像在电子玻璃中通常观察到的那样随时间呈对数形式弛豫。此外，在完全老化模型中，不同光照时间下的弛豫可以进行标度。
