TY - BOOK
T1 - Experimental Methods for Implementing Graphene Contacts to Finite Bandgap Semiconductors
AU - Meyer-Holdt, Jakob
PY - 2016
Y1 - 2016
N2 - Present Ph.D. thesis describes my work on implanting graphene as electrical contact
to finite bandgap semiconductors. Different transistor architectures, types of
graphene and finite bandgap semiconductors have been employed. The device
planned from the beginning of my Ph.D. fellowship was a graphene-C60 monolayergraphene
vertical transistor named the Carbon Burger. The fabrication of such
device proved increasingly difficult to achieve and many experimental methods to
handle graphene were implemented and improved in attempt to fabricate the
Carbon Burger. In the end, a device platform for molecular electronics with parallel
CVD graphene bottom electrodes with SiO2 passivation was successfully fabricated
and electronically characterized. A functioning Carbon Burger was not achieved.
Along the work on the Carbon Burger, the scope was broadened and focus was put
on implementing graphene contacts to semiconductor nanowires, more specifically,
epitaxially grown InAs nanowires. First, we tried a top down method where CVD
graphene was deposited on substrate supported InAs nanowires followed by selective
graphene ashing to define graphene electrodes. While electrical contact between the
nanowires and graphene was achieved, the contact resistance was higher (>100 kΩ)
than what is achieved for optimum metal contacts (~5 kΩ). We therefore developed
a method to directly grow InAs nanowires on graphitic flakes. This was achieved by
using silver seed particles for epitaxial growth of InAs nanowires on graphitic flakes.
An added benefit of our growth experiment is that the entire growth system
comprising graphitic flakes and nanowires can be transferred to TEM grids for a full
TEM analysis of the growth system as a whole. While time did not allow for an
electronic characterization of the graphene-nanowire system, the epitaxial interface
may provide the ultimate electronic contact between the graphene and nanowires
AB - Present Ph.D. thesis describes my work on implanting graphene as electrical contact
to finite bandgap semiconductors. Different transistor architectures, types of
graphene and finite bandgap semiconductors have been employed. The device
planned from the beginning of my Ph.D. fellowship was a graphene-C60 monolayergraphene
vertical transistor named the Carbon Burger. The fabrication of such
device proved increasingly difficult to achieve and many experimental methods to
handle graphene were implemented and improved in attempt to fabricate the
Carbon Burger. In the end, a device platform for molecular electronics with parallel
CVD graphene bottom electrodes with SiO2 passivation was successfully fabricated
and electronically characterized. A functioning Carbon Burger was not achieved.
Along the work on the Carbon Burger, the scope was broadened and focus was put
on implementing graphene contacts to semiconductor nanowires, more specifically,
epitaxially grown InAs nanowires. First, we tried a top down method where CVD
graphene was deposited on substrate supported InAs nanowires followed by selective
graphene ashing to define graphene electrodes. While electrical contact between the
nanowires and graphene was achieved, the contact resistance was higher (>100 kΩ)
than what is achieved for optimum metal contacts (~5 kΩ). We therefore developed
a method to directly grow InAs nanowires on graphitic flakes. This was achieved by
using silver seed particles for epitaxial growth of InAs nanowires on graphitic flakes.
An added benefit of our growth experiment is that the entire growth system
comprising graphitic flakes and nanowires can be transferred to TEM grids for a full
TEM analysis of the growth system as a whole. While time did not allow for an
electronic characterization of the graphene-nanowire system, the epitaxial interface
may provide the ultimate electronic contact between the graphene and nanowires
UR - http://rex.kb.dk/KGL:KGL:KGL01009230964
M3 - Ph.D. thesis
BT - Experimental Methods for Implementing Graphene Contacts to Finite Bandgap Semiconductors
PB - Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen
CY - København, Danmark
ER -