Sensitivity Properties of Graphene with Metal Nanoparticles

Authors N.N. Konobeeva , A.S. Kulbina, I.V. Zaporotskova , M.B. Belonenko

Volgograd State University, 400062 Volgograd, Russia

Issue Volume 11, Year 2019, Number 6
Dates Received 20 March 2019; revised manuscript received 03 December 2019; published online 13 December 2019
Citation N.N. Konobeeva, A.S. Kulbina, I.V. Zaporotskova, M.B. Belonenko, J. Nano- Electron. Phys. 11 No 6, 06021 (2019)
PACS Number(s) 61.72.S –, 73.22.Pr
Keywords Graphene nanoribbon (3) , Conductivity (43) , Metal particles.

In this paper, we investigate the influence of metal nanoparticles on the sensitivity properties of graphene with respect to gas molecules adsorbed on its surface on the example of copper nanoparticles. The influence of the metal atom is taken into account by changing the hopping integral for the regions adjacent to it. Such features are due to the presence of a metal nanoparticle on the surface of a graphene nanoribbon which changes the hybridization of pi electrons in the immediate vicinity of the adsorption site of a metal atom. First of all we use the transition from a two-dimensional array corresponding to the sites of the graphene plane to a one-dimensional array for the determination of the density of states of the system under consideration. Secondly, we are based on the numerical diagonalization of the Hamiltonian for rectangular graphene nanoribbon in the tight-binding approximation. It allows us to estimate the response of the system based on the current-voltage characteristic for the tunneling contact of the graphene nanoribbon with different materials. In this paper we choose metal and quantum dots. The best results have been demonstrated in terms of sensitivity to adsorbed gas molecules for contacts with these materials. In this case, the tunnel current density is calculated from the density of states of the system. Decorating the graphene plane with copper nanoparticles significantly changes the resistance in the tunneling contact of the nanoribbon with the quantum dots or with the metal. Also we observe an increase in the sensitivity of graphene nanoribbons to impurities with an increase in the concentration of metal nanoparticles. Thus, we propose an approach based on the study of tunneling current, which has several advantages, since it allows optimizing the choice of the second sample to achieve the highest sensitivity. Equally important is the fact that various types of contacts may be more optimal for determining various types of impurities.

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