III-V Semiconductor Nanowire for Solid Oxide Fuel Cells R. Muhammad, a, * Y. Wahab, b Z. Othaman, a S. Sakrani a , Z. Ibrahim a a Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM, Johor, Malaysia b Razak School, Universiti Teknologi Malaysia, 54100 Kuala Lumpur, Malaysia *Corresponding author: rosnita@utm.my Abstract Solid oxide fuel cells (SOFC) have much promise as efficient devices for the direct conversion of the energy stored in chemical fuels into electricity. The development of highly robust SOFC that can operate on a range of fuels, however, requires improvement in the electrodes, especially the anode, where nanoscale engineering of the structure is required in order to maximize the number of sites where the electrochemical reactions take place. In this article, we briefly explained the growth of III-V semiconductor nanowire layer on GaAs substrate as an anode electrodes using metal organic chemical organic vapor deposition (MOCVD). Field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and conductivity atomic force microscopy (CAFM) analysis were carried out to investigate the structural properties and current-voltage changes in the wires. Results show that the III-V nanowires grow with less defect structure, uniform in composition and diameters with optimal growth parameters. The current-voltage measurement showed similar to that of a p-n junction characteristic which is suitable in the SOFC application. Keywords: Solid oxide fuel cell; MOCVD; III-V Semiconductor; Nanowire; VLS Technique 1.0 INTRODUCTION Fuel cells are electrochemical reactors in which the energy contained in the chemical bonds within a fuel is converted directly into electrical energy. Fuel cells are inherently more efficient than most other methods of extracting energy from fuels and there has been much recent interest in the development of fuel cells as a more environmentally friendly energy conversion technology. From the multiple types of fuel cells, solid oxide fuel cells (SOFC) is one of the most attention received in recent years. 1-3 SOFC use of oxygen ion (O 2- ) conducting ceramic membrane as the electrolyte. While they also can be powered using hydrogen they are inherently more fuel flexible and can in principle be powered by any combustible fuel including natural gas, liquid hydrocarbon and even solids derived from coal or biomass. 4 This fuel flexibility has led to SOFC being considered for a variety of distributed power applications. While the fuel flexibility of SOFC is one of their advantages, achieving robust system that can operate on a range of fuels for long periods requires nanoscale control of electrode structures and careful choice of the materials that are used in the anode where fuel combustion occurs. 5 The emergence of nanotechnology in recent decades has given a great deal of new insight into theories previously widely assumed by the scientific community. This has resulted in industry showing considerable interest in nanostructured materials. 6 The use of nanomaterials has typically been restricted to low temperature devices, however advances in solid oxide fuel cells (SOFC) such as lowering operating temperatures allow new possibilities for their application. 7 The most advantageous