Conferencia: "Template-assisted fabrication and characterization of polymer nanopillar arrays for optoelectronic applications"
Dr. Lluís Marçal (Catedrático de la Universidad Rovira i Virgili, Tarragona, Departamento de Ingeniería Electrónica, Eléctrica y Automática)
Seminario del cicCartuja - 1ª Planta
Viernes, 25 de marzo de 2011 - 12:00 h.
Abstract: Recently, photoluminescent conducting polymeric micro- and nanostructures have received a considerable attention because of their interesting optoelectronic properties and potential applications such as sensors, polymer light-emitting diodes, polymer solar cells, etc. Different synthesis methods have been proposed for the fabrication of polymer nanostructures: template-assisted, nanoimprinting, nanolithography and electro-spinning. Among them, template-assisted is an easy, low cost, and highly versatile method to fabricate nanostructures for a variety of materials: polymers, metals, inorganics, semiconductors and their multi-functional composites. This method entails microporous or nanoporous materials used as templates. The synthesized nanostructure is achieved by infiltration of the material within the pores of the template. After deposition, the template can be selectively removed either partially or completely to produce a nanostructure array or freestanding nanostructures. In addition, template-assisted techniques possess the advantage of being able to readily create large-area, ordered nanostructures and, in some cases, vertically aligned structures having high aspect ratios.
Anodized aluminium oxide (AAO) has become one of the most common nano-templates for the preparation of different nanometer-sized structures attractive because of its simple and highly controllable fabrication method. Dimensions as well as geometry of the nanostructures such as pore diameter and interpore distance can be controlled by selecting appropriate anodization conditions.
We present the fabrication and characterization of photoluminescent conducting polymer nanopillar arrays via template-assisted method. Different type of polymer nanopillar arrays were fabricated. The resulting polymer nanostructures are analyzed in detail by ESEM (environmental scanning electron microscopy) and AFM (atomic force microscopy) images. The effect of the nano-confinement on the electrical and optical properties is analyzed by current sensing atomic force microscopy (CS-AFM), photoluminescence and UV-Visible spectroscopy. In addition, the orientation of the polymer chains inside the nanopillar is also characterized by Raman spectroscopy and X-ray diffraction (µXRD). The results are discussed and compared with polymer thin films.