Nanocomposites and nanomaterials

Low-temperature study of electrical properties of porous silicon/graphene-based nanostructures
I.B. Olenych, L.S. Monastyrskii, O.I. Aksimentyeva, I.S. Girnyk, Yu.I. Eliyashevskyy, M.S. Rudko
Ivan Franko National University of Lviv. 50 Dragomanov Str., Lviv-79005, Ukraine. E-mail: iolenych@gmail.com

Graphene and graphene-based materials have been attracting great research interest with regard to their outstanding electronic and optical properties which lead to the expansion of their applications in diverse fields. In particular, hybrid materials combining graphene and porous semiconductors such as porous silicon (PS) are promising in photoreceivers and biochemical sensors, field effect transistors and electrodes for power sources [1–3]. The study of charge transfer processes in nanocomposites based on graphene oxide (GO) and reduced graphene oxide (RGO) is a key to the creation of a new generation of devices for nanoelectronics and allows to make their manufacture technology reliable and controlled. 
In this work the GO/PS and RGO/PS hybrid nanostructures are implemented in order to investigate their electrical properties in both DC and AC modes and temperature range of the 12–300 K. A topology of the porous silicon/graphene-based nanostructures was characterized by scanning electron microscope (SEM) and atomic-force microscope (AFM). Based on temperature dependences conductivity of the hybrid nanostructures, a hopping conductivity and activation mechanism of charge transport in different temperature ranges were established and the activation energy of the conductivity was determined. By means of impedance spectroscopy it is shown that the impact of the graphene-based nanoparticles on electrical characteristics of PS is manifested in the capacitance and internal resistance change of the hybrid structures in wide temperature range.

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2.	Olenych I.B., Aksimentyeva O.I., Monastyrskii L.S., Horbenko Yu.Yu., Partyka M.V., Luchechko A.P., Yarytska L.I. Effect of graphene oxide on the properties of porous silicon // Nanoscale Res Lett.-2016.-11.-43. 
3.	Olenych I.B., Aksimentyeva O.I., Monastyrskii L.S., Horbenko Yu.Yu., Partyka M.V. Electrical and photoelectrical properties of reduced graphene oxide – porous silicon nanostructures // Nanoscale Res Lett.-2017.-12.-272.