Coupling between structural properties and charge transport in nano-crystalline and amorphous graphitic carbon films, deposited by electron-beam evaporation

V V Brus; M I Ilashchuk; I G Orletskyi; M M Solovan; G P Parkhomenko; I S Babichuk; N Schopp; G O Andrushchak; A I Mostovyi; P D Maryanchuk

doi:10.1088/1361-6528/abb5d4

Coupling between structural properties and charge transport in nano-crystalline and amorphous graphitic carbon films, deposited by electron-beam evaporation

Nanotechnology. 2020 Dec 11;31(50):505706. doi: 10.1088/1361-6528/abb5d4.

Authors

V V Brus¹, M I Ilashchuk², I G Orletskyi², M M Solovan², G P Parkhomenko², I S Babichuk^{3

4}, N Schopp⁵, G O Andrushchak², A I Mostovyi², P D Maryanchuk²

Affiliations

¹ Department of Physics, School of Sciences and Humanities, Nazarbayev University, Nur-Sultan, Kazakhstan.
² Department of Electronics and Energy Engineering, Chernivtsi National University, Chernivtsi, Ukraine.
³ V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kyiv, Ukraine.
⁴ Faculty of Intelligent Manufacturing, Wuyi University, Jiangmen, People's Republic of China.
⁵ Center for Polymers and Organic Solids, University of California Santa Barbara, Santa Barbara, United States of America.

PMID: 32924974
DOI: 10.1088/1361-6528/abb5d4

Abstract

Nano-crystalline and amorphous films of graphitized carbon were deposited by electron-beam evaporation of bulk graphite. Structural properties and the size of graphite nanoclusters (L ≈ 1.2-5 nm) in the films were determined from the analysis of their Raman spectra. Electrical properties of the bulk nano-crystalline graphite reference sample and the deposited graphitic carbon films were measured by means of the Hall effect technique within the temperature range from 290 to 420 K. The electrical conductivity σ and Hall mobility μ_H of all samples exhibited exponential temperature dependences, indicating on the non-metallic behavior. Electrical properties of the amorphous graphitic carbon thin films, deposited at low substrate temperatures (620 and 750 K) were analyzed in the scope of the hopping charge transport mechanism via localized states. We have shown that the charge transport in the bulk and thin film (920 K) nano-crystalline graphite samples is carried out via the tunneling and thermionic emission over potential barriers at the grain boundaries.This paper contributes towards better understanding of coupling between structural and electrical properties of graphitic carbon thin films.