Open AccessEffect of additional annealing on the electrophysical properties of large-size CVD-graphene samples
Author(s) -
D.N. Tonkov,
V. É. Gasumyants
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1851/1/012017
Subject(s) - graphene , annealing (glass) , materials science , electrical resistivity and conductivity , impurity , semiconductor , scattering , condensed matter physics , nanotechnology , composite material , chemistry , optoelectronics , optics , physics , organic chemistry , quantum mechanics
This paper is devoted to the comparative study of the resistivity temperature dependences for large-size 1–2 layered graphene samples prepared by the CVD method and subjected to additional annealing in an Ar/H mixture at different temperatures. The influence of the annealing temperature on the temperature dependences of resistivity was qualitatively analyzed for two types of initial samples demonstrating a metallic- or semiconductor-like ρ( T ) dependence. This made it possible to elucidate the processes occurring in the samples upon annealing, as well as to assess the degree of their influence on the electrical properties of the annealed samples. This analysis showed that the main processes initiated by annealing are the formation of additional defects and cleaning of the graphene surface. To confirm this conclusion, we performed a numerical analysis of the experimental ρ( T ) dependences, based on a model taking into account different scattering mechanisms of charge carriers in graphene samples. This allowed us to determine the concentrations of impurities on the graphene surface and defects in the graphene crystal structure for all investigated samples. The character of the change in these values depending on the annealing temperature for samples with different types of the ρ( T ) dependence is discussed.