Nanocomposites and nanomaterials

Electrical and photoelectric properties of hybrid structures based on reduced graphene oxide and doped porous silicon
I.B. Olenych1, Yu.Yu. Horbenko2
1 Electronics and Computer Technologies Department, Ivan Franko National University of Lviv, 50 Dragomanov Str., Lviv-79005, Ukraine
E-mail: iolenych@gmail.com
2 Chemistry Department, Ivan Franko National University of Lviv, 6 Kyrylo and Mefodiy Str., Lviv-79005, Ukraine 

Useful properties of hybrid structures combining graphene and porous semiconductors, in particular, porous silicon (PS) have caused the emergence of potential applications, ranging from photoreceivers and chemical sensors to field-effect transistors and electrodes for power sources [1-3]. Graphene is effectively used as a transparent electrode in displays and photonic devices due to its outstanding optical properties. Besides, the conical shape of the electron spectrum of graphene determines the most unique properties of graphene as a gapless semiconductor. In particular, it is possible to easily control the electrical conductivity of graphene and inject carriers with a positive or negative charge by means of a local electric field. This feature of graphene can be used to create a new type of photodetectors. 
In this work, the PS–reduced graphene oxide (rGO) hybrid structures were created and their electrical properties were studied in both DC and AC modes. Graphene field effect transistors in obtained structures were used as a light photon detector. The influence of back-gate voltage and doping of the PS layer with metals on the electrical and photoelectric properties of the PS–rGO structures has been studied. The electrical conductivity of the PS–rGO hybrid structures depends not only on the direct collection of charges but also on the change in the graphene conductivity due to the local electric field of photogenerated charge carriers. 

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2.	Ge D. et al. Fabrication of graphene/porous silicon nitride material for field-effect transistors // ECS Transactions.-2016.-72.-257.
3.	Olenych I.B. et al. Charge Transport in Porous Silicon/Graphene-Based Nanostructures // Mol. Cryst. Liq. Cryst.-2018.-673.-32.