Evaluation of surface control and durability of carbon nanotube and indium tin oxide coated polyethylene terephthalate transparent electrodes under different drying conditions

Abstract

Transparent electrodes using carbon nanotube (CNT) have recently been studied as potential replacements for conventional indium tin oxide (ITO). In this work, CNT and ITO coated polyethylene terephthalate samples were prepared and studied. The degree of cohesion is dependent on the drying conditions. To explore affects of changing surface conditions, three drying temperatures, 20, 80, and 120 degrees C, were used. Electrical resistance measurements were used to evaluate the interfacial durability and electrical properties of prepared transparent electrodes. A field emission scanning electron microscope was used to investigate surface changes and UV-spectroscopy was used to evaluate transparency as functions of the different drying temperatures. The electronic properties for these nanoparticle coated surfaces were evaluated using a cyclic voltametry method. Interfacial durability was evaluated by static contact angle measurement versus elapsed time. The pH values of the coatings were measured in a water solution. The durability of the CNT coated surfaces was found to be better than that of the ITO coated surfaces. The higher drying temperatures were found to produce better coated surfaces because of improved cohesion between the nanoparticles which resulted in improved electrical properties and improved durability. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.JMM.11.2.023010]