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Open access

Umber Kalsoom, M. Shahid Rafique, Shamaila Shahzadi, Khizra Fatima and Rabia ShaheeN

Abstract

The objective of the present research work is to optimize the growth conditions of bi- tri- and few-layer graphene using pulsed laser deposition (PLD) technique. The graphene was grown on n-type silicon (1 0 0) at 530 °C. Raman spectroscopy of the grown films revealed that the growth of low defect tri-layer graphene depended upon Ni content and uniformity of the Ni film. The line profile analysis of the AFM micrographs of the films also confirmed the formation of bi- tri- and a few-layer graphene. The deposited uniform Ni film matrix and carbon/Ni thickness ratio are the controlling factors for the growth of bitri- or few- layer graphene using pulsed laser deposition technique.

Open access

Riffat Sagheer, M. Shahid Rafique, Farhat Saleemi, Shafaq Arif, Fabian Naab, Ovidiu Toader, Arshad Mahmood, Rashad Rashid and Irshad Hussain

Abstract

Ion implantation has a potential to modify the surface properties and to produce thin conductive layers in insulating polymers. For this purpose, poly-allyl-diglycol-carbonate (CR-39) was implanted by 400 keV Au+ ions with ion fluences ranging from 5 × 1013 ions/cm2 to 5 × 1015 ions/cm2. The chemical, morphological and optical properties of implanted CR-39 were analyzed using Raman, Fourier transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM) and UV-Vis spectroscopy. The electrical conductivity of implanted samples was determined through four-point probe technique. Raman spectroscopy revealed the formation of carbonaceous structures in the implanted layer of CR-39. From FT-IR spectroscopy analysis, changes in functional groups of CR-39 after ion implantation were observed. AFM studies revealed that morphology and surface roughness of implanted samples depend on the fluence of Au ions. The optical band gap of implanted samples decreased from 3.15 eV (for pristine) to 1.05 eV (for sample implanted at 5 × 1015 ions/cm2). The electrical conductivity was observed to increase with the ion fluence. It is suggested that due to an increase in ion fluence, the carbonaceous structures formed in the implanted region are responsible for the increase in electrical conductivity.