Structural, morphology and optical properties of ITO/PEDOT:PSS and ITO/Ag nanoparticles/PEDOT:PSS thin films

¹ Atomic and Molecular Group, Department of Physics, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran
² Department of Physics, College of Sciences, Shiraz University, Shiraz 71454, Iran

^a e-mail: malekfar@modares.ac.ir

Received: 3 August 2012
Revised: 3 November 2012
Accepted: 21 January 2013
Published online: 8 March 2013

Abstract

In order to investigate the effects and optical properties in the mid-infrared region, thin films of PEDOT:PSS were spin-coated on ITO glasses and ITO/Ag nanoparticles substrates. Scanning Electron Microscopy, SEM, has been applied to investigate the surface morphology and measure the size of nanoparticles. Dielectric and optical coefficients such as refractive index, n, and extinction coefficient, k, were calculated by applying Kramers-Kronig dispersion relations to the experimentally recorded near normal reflection FTIR spectra. Different analyses confirm that Ag nanoparticles are present in the structure of the synthesized thin films. The recorded Raman spectra have shown that the intensity enhancement of Raman peaks of PEDOT:PSS increases due to the plasmon resonance of Ag colloidal silver nanoparticles layer and optical properties investigation has confirmed the electrical conductivity increase in the mid-infrared region.