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conferenceseries.com Joint Conference
July 17-18, 2017 Chicago, USA
International Conference on
DIAMOND AND CARBON MATERIALS & GRAPHENE AND SEMICONDUCTORS
Volume 6, Issue 6 (Suppl) J Material Sci Eng, an open access journal
ISSN: 2169-0022
Diamond and Carbon 2017 & Graphene 2017
July 17-18, 2017
J Material Sci Eng 2017, 6:6(Suppl)
DOI: 10.4172/2169-0022-C1-077
Encapsulation and real life reproducibility of graphene devices
Abhay A Sagade
University of Cambridge, UK
As many graphene-based electronic and optoelectronic device concepts begin to make the transition from the research
laboratory into real world applications it is imperative that factors such as long term stability and large area reproducibility
are addressed. Graphene is inherently highly sensitive to environmental factors such as ambient air, lithography resists and
polymers used in the transfer process which cause unintentional, generally p-type, doping and hysteretic behavior in field effect
devices. Many of the graphene field devices need ambi-polarity. To overcome these issues device encapsulation and passivation
is required. Atomic layer deposition (ALD) of oxides provides two-fold benefits. Firstly, Al2O3 act as a moisture barrier which
adds long term stability and protection of devices from humidity and other atmospheric effects. Secondly, the ALD process has
been shown to effectively passivate charge trap sites such as silanol (SiOH-) groups at the SiO2—graphene interface which are
responsible for much of the observed unintentional doping and hysteretic device behavior. We have developed two different
routes to enhance the nucleation of ALD oxides on hydrophobic graphene surface. In first approach an ex-situ nucleation
layer of 2 nm Al film was deposited with appropriate amount of oxygen control by e-beam evaporation. While in second route
an in-situ nucleation was created by pulsing water precursor in the ALD chamber. In both the methods highly-air stable and
reproducible GFETs are obtained. We have shown continuous hundreds of DC measurements in ambient which do not show
any hysteresis and shifts of Dirac points with negligible doping concentration in graphene channel. It paves the way to speed
up the production of graphene devices for real life applications.
Graphene and boron nitride-based nanocomposites with enhanced thermal properties
Pradip Majumdar2 and Amartya Chakrabarti1
1Applied Material Systems Engineering Inc., USA
2Northern Illinois University, USA
Polymer composites with a high thermal conductivity are always desired for different applications. Improved thermal
conductivity of polymers can be obtained via dispersion of metal particles in a polymer matrix. However a good dispersion
and thermal coupling cannot be have designed anddeveloped a formulationwith enhanced thermal conductivity of
silicone and epoxy-based resin systems using graphene and boron nitride-based nanomaterials synthesized in our laboratories.
The nanocomposites are characterized thoroughly and excellent thermal conductivity improvement was observed. A detailed
data analysis with different characterization techniques will be discussed and demonstrated.