Hopping Conductivity Mechanism in Cd3As2 Films Prepared by Magnetron Sputtering

Authors V.S. Zakhvalinskii1 , E.A. Pilyuk1, T.B. Nikulicheva1, S.V. Ivanchikhin1, M.N. Yaprintsev1 , I.Yu. Goncharov1,2 , D.A. Kolesnikov1 , A.A. Morocho1, О.V. Glukhov3

1Belgorod National Research University, 85, Pobedy St., 308015 Belgorod, Russia

2Belgorod State Technological University Named After V.G. Shukhov, 46, Kostyukova St., 308012 Belgorod, Russia

3 National University of Radioelectronics, 14, Science Boulevard, 61166 Kharkiv, Ukraine

Е-mail pilyuk@bsu.edu.ru
Issue Volume 12, Year 2020, Number 3
Dates Received 07 March 2020; revised manuscript received 15 June 2020; published online 25 June 2020
Citation V.S. Zakhvalinskii, E.A. Pilyuk, et al., J. Nano- Electron. Phys. 12 No 3, 03029 (2020)
DOI https://doi.org/10.21272/jnep.12(3).03029
PACS Number(s) 68.37. − d, 72.20. − i
Keywords Cadmium arsenide (2) , Dirac semimetals, Thin films (60) , Hopping conductivity.

Cadmium arsenide films on oxidized silicon substrates were obtained by RF magnetron sputtering. The structure and morphology of the surface were studied by atomic force microscopy (AFM) and Raman spectroscopy (RS). The Raman spectrum contains peaks characteristic for Cd3As2 films at 194, 249, and 303 cm − 1. The carrier mobility in the samples was 0.15-1.7·103 cm2V − 1s − 1 at concentrations of 0.7-4.4·1019 cm − 3. It has been established that for the sample No 1 in the temperature range T  10-15 K, the variable-range hopping (VRH) conductivity mechanism according to the Mott law is implemented. This can be explained by the fact that a microscopic disorder becomes important for electron localization in this temperature region. This is due to a decrease in temperature or an increase in the degree of disorder. In this case, the jump becomes possible only inside the Mott energy band near the Fermi level. The charge transfer in sample No 2 at T  220-300 K is carried out by the VRH conductivity of the jump over localized states lying in a narrow energy band near the Fermi level. These states can be created by grain boundaries and dislocations. The relations between the values of the Coulomb gap Δ and the zone width of localized states W are consistent with the corresponding conduction mechanism.

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