Structure and Optical Properties of Nanocomposite Carbon Films Obtained from Accelerated C60 Ion Flows Svetlana Rudchenko1; Vladimir Egorovich Pukha1; Vadym V. Starikov1; Athanasios G. Mamalis2; Sergiy N. Lavrynenko3; 1NATIONAL TECHNICAL UNIVERSITY - KHARKOV POLYTECHNIC INSTITUTE, Kharkiv, Ukraine; 2PC-NAE, DEMOKRITOS NATIONAL CENTER FOR SCIENTIFIC RESEARCH, Athens, Greece; 3KHARKOV POLYTECHNIC INSTITUTE, Kharkov, Ukraine; PAPER: 151/Manufacturing/Regular (Oral) SCHEDULED: 12:10/Tue./Sao Conrado (50/2nd) ABSTRACT: The results of structural and optical investigations of thin carbon films deposited from the mass-separated beam of accelerated C60 ions with energy of 5 keV are presented. The substrate temperature ranged from 100°C to 400°C. It was established that change of the TS from 100°C to 400°C leads to the consecutive formation of diamond-like carbon (DLC) films with amorphous state and superhard nanocomposites consisting nanographite structures (1-2 nm) surrounded by a diamond-like amorphous matrix. For amorphous films the band gap (Eg) was in the range of 1.2 - 1.4 eV. For nanocomposite films on optical absorption spectra, there are two energy components: one with a narrow Eg = 1 eV, which is associated with three-dimensional nanocrystals of graphite, and the other - with a wide optical gap (Eg =3,45-3,55 eV) that corresponds to the diamond-like amorphous matrix of nanocomposite. According to the results of scanning tunneling microscopy (STM) and tunnel spectroscopy (TS), the size of graphite nanocrystals is about 1-2 nm and an amorphous shell around the graphite nanocrystals had a thickness of about 1.5 nm. The graphite component had n-type conductivity and an amorphous component had p-type conductivity. The electrical conductivity of such semiconductor nanocomposite was 103 S/m that to 6 orders higher compared to the DLC film in the amorphous state. References: [1] Robertson J. Diamond-like amorphous carbon // Materials science and Engineering. 2002. R37. Р.129-281. [2] Robertson J. and O'Reilly E.P. Electronic and atomic structure of amorphous carbon // Phys. Rev. B. 1987. Vol.35, 6. P.2946-2957 [3] Robertson J. Electronic and atomic structure of diamond-like carbon // Semicond. Sci. Technol. 2003. Vol.18. Р.S12-S19. [4] Tay B.K. Optical properties of tetrahedral amorphous carbon films determined by spectroscopic ellipsometry / Tay B.K., Shi X., Cheah L.K., Flynn D.I. // Thin Solid Films. 1997. Vol.308. Р.268-272. [5] Teo K.B.K. Highest optical gap tetrahedral amorphous carbon / Teo K.B.K., Ferrari A.C., Fanchini G., Rodil S.E., Yuan J., Tsai J.T.H., Laurenti E., Tagliaferro A., Robertson J., Milne W.I. // Diamond and Related Materials. 2002. 11. P.1086-1090. |