Nanostructure Evolution and Optical Properties of Silver Doped Diamond Like Carbon Thin Film on Soft Polymer

Abstract

Effect of silver doping on nanostructure evolution and optical properties of diamond like carbon films synthesized on elastomeric polymer of poly-dimenthylsiloxane (PDMS) and silicon substrate via radio frequency reactive sputtering technique were studied in detail. Due to difference in elastic moduli of PDMS substrate and silver doped diamond like carbon (Ag:DLC) films, a well-defined nanostructure wrinkle pattern have formed on PDMS for releasing the strain energy induced by residually compressed stress in Ag:DLC film. X-ray photoelectron spectroscopy analysis revealed the different bonding information between silver and carbon and the chemical composition of the Ag:DLC films. The introduction of silver in the DLC matrix, decreased the optical transparency as well as the optical band gap from 3.97 to 3.25 eV with a variation of Ag at.% from 0 to 9.2 in the films. The Urbach parameter calculated from the transmitance data, increased with the increase of the Ag doping percentage.