Graphene group
Introduction1. What do we manage (technology)?2. What do we manage in cooperation
(technology)?3. What are our scientific topics?
Some interesting examples
Examples: CVD growth
Best result: average diameter of Cu grain and corresponding graphene monocrystal = 10 mm
Transfer on SiO2 (300 nm)/Si
Procházka et al. - Nanotechnology 25, 18, (2014)
Examples: KPFM in ambientCharging (RH = 5 %; t = 5 minutes ) Discharging and charge transfer (RH = 30 % )
Examples: Sensors
graphene sensitivity
GO 30 %
CVD graphene 2 %
Exfoliated graphene < 1 %
Resistance response on RH change (20 -> 70 %)
Sensors designs Response on RH2 point
4 point
Examples: Transport meas. Pumping and annealing Atmosphere exposition
Temperature influence Magnetic field at low temp.
Examples: Solar cells• Based on Schottky junction (difference between electron work
function) between CVD graphene and silicon. • Achieved efficiency at our faculty is around η = 0.8 %.
Sample I-V curve
SEM EBIC
Examples: Deposition Ga and GaN on graphene
Deposition of 12 ML of Ga at 300°C
• Effusion cell Ga • Low energy ion source (N2
+, E = 50 eV)• UHV conditions• RT- 400 oC
On exfoliated multilayer graphene
On CVD monocrystal of graphene
Raman spectra of the graphene sheets after the deposition of Ga. The intensity is significantly enhanced.
The XPS spectrum of a graphene’s valence band.