Graphene and ZnO Nanostructures for Nano- Optoelectronic & Biosensing Applications

University dissertation from Linköping : Linköping University Electronic Press

Abstract: There has been a remarkable excitement in graphene research since the famous discovery in 2004 by isolating a monolayer with the help of scotch tape. Graphene, merely a single layer of carbon atoms, is progressively making inroads into a wide range of applications, from ballistic electronics to biosensors to flexible/transparent displays. Graphene is a matchless material that is strong, light, transparent, and an excellent conductor of heat and electricity. On the other hand, zinc oxide (ZnO) is a wide band semiconductor that demonstrates excellent electrical, optical, catalytic and sensing properties and has numerous applications in various fields. ZnO is a natural n-type semiconductor due to the presence of intrinsic defects such as Zn interstitials and O vacancies that also contribute strongly to optical emissions in the visible region.The amalgamation of the exceptional properties of graphene with good semiconducting properties of ZnO can pave the way towards the realization of future devices (LED, biosensors, photovoltaics etc.).In this thesis, graphene nanosheets and zinc oxide (ZnO) nanostructures have beensuccessfully synthesized by using chemical vapor deposition (CVD), vapor liquidsolid (VLS) or wet chemistry routines. These nanostructures were used to fabricatenano and optoelectronic devices, including field effect transistors (FETs), lightemitting diodes (LEDs), UV detectors and biosensors. Both nanomaterial’s propertiesand performances of the devices have been characterized and reported.