Impact of Argon gas on optical and electrical properties of Carbon thin films

• Published in: Physica. B, Condensed matter Condensed matter, 2016-12, Vol.503, p.157-161
• Main Authors: Usman, Arslan, Rafique, M.S., Shaukat, S.F., Siraj, Khurram, Ashfaq, Afshan, Anjum, Safia, Imran, Muhammad, Sattar, Abdul
• Format: Article
• Language: English
• Subjects: AFM; Argon; Atomic force microscopy; Band gap; Carbon; DLC; Electrical properties; Electrical resistivity; Environmental impact; Gas pressure; Microstructure; Optical Bandgap; Optical properties; PLD; Pulsed laser deposition; Raman Spectroscopy; Surface properties; Thin films
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2016.09.029

Nanostructured thin films of carbon were synthesized and investigated for their electrical, optical, structural and surface properties. Pulsed Laser Deposition (PLD) technique was used for the preparation of these films under Argon gas environment. A KrF Laser (λ=248nm) was used as source of ablation and plasma formation. It was observed that the carbon ions and the background gas environment has deep impact on the morphology as well as on the microstructure of the films. Time of Flight (TOF) method was used to determine the energies of the ablated carbon ions. The morphology of film surfaces deposited at various argon pressure was analysed using an atomic force microscope. The Raman spectroscopic measurement reveal that there is shift in phase from sp3 to sp2 and a decrease in FWHM of G band, which is a clear indication of enhanced graphitic clusters. The electrical resistivity was also reduced from 85.3×10−1 to 2.57×10−1Ω-cm. There is an exponential decrease in band gap Eg of the deposited films from 1.99 to 1.37eV as a function of argon gas pressure.