Synthesis and Optical Characteristics of AgO Thin Films

Synthesis and Optical Characteristics of AgO Thin Films Synthesis and Optical Characteristics of AgO thin films Fabricated by Chemical Bath Deposition Method 1EZENWA I. A., 2OBIAGAUZO P. O. 3EBEH L. N. ABSTRACT Binary thin films of silver oxide using chemical Bath method (CBD) have been grown and characterized. Absorbance spectral data of the films were obtained using a Shimadzu 1800 UV- VIS spectrophotometer. An Olympus optical microscope at 100X magnification was used to examine and produce micrograph of the grown thin, which showed that the films have crystal structure and have small grain sizes. A bandgap of 1.62eV and a refractive index range of 1.1- 2.31were obtained. INTRODUCTION Binary thin films are thin films that contain exactly two different elements. Binary thin film had been grown and characterized by many researchers for various applications, examples are; Ag2S (Ezenwa et al., 2012), FeS (Uhuegbu, 1989), ZnS (Ndukwe 1999), Ag4O3, (Bielmann et al, 2002), Silver being multivalent, have various phases like Ag2O, AgO, Ag3O4, Ag4O3, and Ag2O3 by interacting with oxygen (Bielmann, Scheallar, Ruffieux, Groning, Schlapbach, 2002).These oxides have different crystalline structures leading to a variety of physiochemical, electrochemical, electronic and optical properties. The most observable and stable phases are Ag2O and AgO (Garner and Reeves, 1954). Ag2O thin films have been widely studied due to their wide range of applications. The recent interest in silver oxide is for its potential use in optical memories. Photoactivation of silver oxide leads to nanosilver clusters (Hou, Ouyang, Chen et al 1998).These nanoclusters emit fluorescence and also exhibit plas monic behavior. These properties have a wide application range from ultra high density optical data storage to plasmon photonic devices (Tominaga, 2002).They are also used as a sensor for gas detection and photovoltaic materials, studies have shown that silver oxide films have a wide range of energy band gap of between 1.2 and 3.4eV(Dierson, Rousselot, 2005). The major routes used for silver oxide films deposition are reactive sputtering of silver metal in an oxygen-containing argon atmosphere and electron-beam evaporation of silver metal. Another method is the pulsed laser deposition technique (Raju, Kumar, 2011),this method takes place in gaseous phase, hence requiring high temperatures. These high temperature methods also limit the type of substrates used in high temperature resistant substrates. Alternatively wet chemistry and electrochemical methods have been used as low temperature method.Wet chemistry methods generally require the substrates to be dipped inside the precursor solution for days to form thin film materials at temperatures of up to 200Â °C, while electrochemical deposition grows thin film materials on conductive substrate at lower temperatures (