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

Our technology

3 mm

Technology in cooperation

Our scientific topics

Examples: CVD growthScheme of home-built CVD oven

Graphene growth process

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: Suspended graphene

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.

Ideas for cooperation?