Optics and Photonics Society of Iran

In this study, gold nanoparticles deposited on glass substrates are investigated. The effect of the ambient environment on the annealing process of the gold nanostructured films is studied. The thermally-induced drastic morphology evolutions are followed by scanning electron microscopy. Results reveal that the changes have a great influence on conductivity, optical and structural properties of the prepared structures. UV-Vis absorption spectra are used to investigate the optical properties. The current-voltage (I-V) measurements are performed using a two point probe instrument. The I-V measurement of the unannealed gold nanostructured film has a linear curve that represents a tunneling process. The conductivity of the annealed film in air environment shows a non-ohmic behavior. Results show that the existence of the stable thin oxide layer in Au2O3 phase in the structure of the annealed film plays an important role in the non-ohmic behavior. Annealing in a vacuum chamber and removing the ambient oxygen gas, the behavior of conductivity remains ohmic and its characteristics could be explained by the morphology-dependent tunneling process. The stable optical and electrical properties of these gold nanostructured films could make them useful for many applications i.e., sensors, high-value resistors, voltage fuse, strain gauges and optoelectronic devices