Instituto de Plasmas e Fusão Nuclear,
Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
http://www.ipfn.ist.utl.pt
http://www.facebook.com/IPFNLA
L.L. [email protected]
PLASMA TECHNOLOGIESTailoring matter at nanoscale level
ATHENS@ISTMarch 2015
Plasma
electron
ion
neutral
Plasma : definition (reminder)
Ionized gas, neutral, with collective behaviour
Ionized gaselectrons (hot, ~104 K)ions (cold, ~300 K)neutrals (cold, ~300 K)
Neutral mediumNumber of electrons = number of ions
Collective behaviour ionization level affects electrical properties
Plasmas : classification (reminder)
Low-temperature (discharge) plasmas
E
P x d
E
P x d
Paschen’s law
+ -E
+ -E
Gas, pressure PDistance d between electrodes
Discharge plasmasPaschen’s law
d
Discharge plasmasPlasma reactors
Inductively Coupled Plasma (ICP)rf, low pressure, high density
Inductively Coupled Plasma (ICP)rf, low pressure, high density
Inductively Coupled Plasma (ICP)rf, low pressure, high density
Capacitively Coupled Plasma (CCP)rf, intermediate pressures, low densityCapacitively Coupled Plasma (CCP)
rf, intermediate pressures, low densityCapacitively Coupled Plasma (CCP)
rf, intermediate pressures, low density
Magnetron for sputteringrf, low pressure, high density
Magnetron for sputteringrf, low pressure, high density
Magnetron for sputteringrf, low pressure, high density
Electron-cyclotron resonance (ECR) plasmamicrowaves, low pressure, high density
Electron-cyclotron resonance (ECR) plasmamicrowaves, low pressure, high density
Electron-cyclotron resonance (ECR) plasmamicrowaves, low pressure, high density
Discharge plasmas Applications
Discharge plasma is …
• cold (contact without damage)
• reactive (modification of systems)
• radiation emitter (usage in lightning)
• fluid (very effective interaction)
E (eV)
Energy levels - He and Ne
19
2p53s17
2p55s
2p54p
2p54s23S1
21 21S0
2p53p
1S0 2p61S0
3.39 µm
6328 Å1.15 µm
rápida
E (eV)
Energy levels - He and Ne
19
2p53s17
2p55s
2p54p
2p54s23S1
21 21S0
2p53p
1S0 2p61S0
3.39 µm
6328 Å1.15 µm
rápida
Discharge plasmasApplications: lamps and lasers
• Electron temperature : 1-2 eV• Electron density : 1011 –1012 cm-3
• Gas temperature : ~ 350 K• Gas pressure: 1-2 Torr
Discharge plasmasApplications: material processing / deposition / functionalization
• Silicon dioxide (SiO2)• Silicon nitride, carbide (SiXNYHZ, SiC)• Metallic oxides (ZnO, TiO2, …)• Ceramic thin films (organically modified)
• Polymers• Carbon nanoparticles and nanotubes
Discharge plasmasApplications: material processing / etching
Micro-electronics• Micro-fluidics• Micro-fabrication • Bio-engineering
(tissues, prosthetics)• Optoelectronics and photonics• Detectors and sensors• …
ICP etching 95% Ar + 5% Cl2
Electronegativegas-mixture
Volatileproducts
ICP etching 95% Ar + 5% Cl2
Electronegativegas-mixture
Volatileproducts
Failure analysisSiO2 etching
Failure analysisSiO2 etching
PMMA etching by O2 (120mm)PMMA etching by O2 (120mm)PMMA etching by O2 (120mm)
Discharge plasmasApplications: micro-discharges
E
P x d
E
P x d
d↓ allows…• P↑(Pd typical of macro-discharges
at low-pressure)• low-E � reduced power
but…• high power-density
Portability (miniaturization + atmospheric pressure)
Vast applicability (low power)
Discharge plasmasApplications: micro-discharges
Gaseous detectors
Microwave micro-discharges
ICP micro-discharge
O2(a1D) source
Array with 20 MCSDs(DC micro-discharge)
Mechanical fabrication
Micro-plasma jetCutting tools
Discharge plasmasApplications: plasmas in biologic and biomedical applications
Plasma-assisted bacteriologic treatmentE. coli (a–c), S. epidermidis (d–f) e MRSA (g–i)(a, d, g) – not treated(b, e, h) - treated with plasma during 5s(c, f, i) - treated with plasma during 20s
Sterilization of chirurgic instrumentsby hydrogen peroxide plasmas
Plasma needle
(cosmetics, stimulator,
coagulator, sterilizer)
Discharge plasmasApplications: plasma TV
Discharge plasmasEveryday life applications
PLASMA TECH @ IPFN
IPFN organization
Instituto de Plasmas
e Fusão NuclearInstituto de Plasmas
e Fusão Nuclear
Engineering & Systems Integration
Engineering & Systems Integration
Lasers & PlasmasLasers & Plasmas
Gas Discharges and Gaseous ElectronicsGas Discharges and Gaseous Electronics
High-pressure PlasmasHigh-pressure Plasmas
Laboratory of Quantum Plasmas
Laboratory of Quantum Plasmas
Theory & ModelingTheory & Modeling
Experimental PhysicsExperimental Physics
Material Characterization
Material Characterization
Governing BoardGoverning Board
Scientific CouncilScientific Council
PresidentPresidentExternal Advisory
PanelExternal Advisory
Panel
Controlled Nuclear Fusion
Controlled Nuclear Fusion
Intense Lasers and Plasmas
Technologies
Intense Lasers and Plasmas
Technologies
GEDG
GEDGOrganization / activities
Plasma Engineering Laboratory
PIs: E Tatarova, FM Dias
Hypersonic Plasma LaboratoryPI: ML Silva
Modeling & Simulation
PIs: ML Silva, V Guerra
Head: LL Alves
Plasma Engineering Laboratory
Plasma Engineering LaboratoryMicrowave plasma-based single-step method for free-standing graphene synthesis
•Versatile method to generate self standing graphene sheets at atmospheric conditions
• Rigid control of graphene structural quality
HRTEM observation of samples produced from ethanol
1 layer
Graphene flakes freely suspended on the grid
Plasma Engineering LaboratoryMicrowave plasma-based single-step method for free-standing graphene synthesis
We use microwave plasmas to effectively decompose hydrocarbon molecules
The plasma environment creates extraordinary assembly pathways and nanostructures
Plasma Engineering LaboratoryMicrowave plasma-based single-step method for free-standing graphene synthesis
Graphene is produced downstream using a single-step method in atmospheric conditions
Free-standing graphene sheets with highly-ordered lattice fringes and few mono-layers
92 96 100 104 108 112 116 120 124 1280,00
0,01
0,02
0,08
0,10
0,12
Lα
Inte
nsity
(a.
u.)
Wavelength (nm)
Ar + % H2P=260W, p=0.35mbar
5% 30%
Lβ Ar
Ar
theory
Ar resonant lines vs power
Plasma Engineering LaboratoryMicrowave plasmas as source of extreme VUV radiation
Extreme VUV wavelengths are obtained when using Ar-H2 plasmas
Modelling & Simulation
Modeling & simulation
We master the simulation and modelling of various plasma sources using complex kinetic schemes
Exceptional UV production and guidance
Power density ~0.1 MW cm-3 for Tg < 1500 K
Analysis of gas heating
2.35 2.40 2.45 2.50 2.550.0
0.2
0.4
0.6
0.8
1.0
Rel
ativ
e co
uple
d po
wer
f (GHz)
Modelling & simulationMicrowave-driven plasmas in hollow-core photonic crystal fibres
0.00 0.01 0.02 0.03 0.04500
800
1100
1400
1700
Test structure400 µm
Tg (
K)
r (cm)
Kagomé fibre50 µm
0.00 0.01 0.02 0.03 0.04500
800
1100
1400
1700
Test structure400 µm
Tg (
K)
r (cm)
Kagomé fibre50 µm
0 1 2 3 40.0
0.2
0.4
0.6
0.8
1.0
Inte
nsit
y S
PS
(0,0
) (a
.u.)
z (cm)
N2N2 1 mbar0.2 mbar1 mbar0.2 mbar
0 1 2 3 40.0
0.2
0.4
0.6
0.8
1.0
Inte
nsit
y S
PS
(0,0
) (a
.u.)
z (cm)
N2 1 mbar0.2 mbar
N2 and N2-H2 ccrf discharges
Towards Titan’s atmosphere at lab scale
Calculated and measured time-average:SPS(0,0) vs. axial position (top-left);FNS(0,0) vs. H2 percentage (top-right);self-bias voltage vs. power coupled (bottom)
0 1 2 3 4 50.5
1.0
1.5
2.0
2.5
H2/(H
2+N
2) (%)
Inte
nsit
y FN
S(0,
0) (
a.u)
N2-H2N2-H2
1.2 mbar0.6 mbar1.2 mbar0.6 mbar
0 1 2 3 4 50.5
1.0
1.5
2.0
2.5
H2/(H
2+N
2) (%)
Inte
nsit
y FN
S(0,
0) (
a.u)
N2-H2
1.2 mbar0.6 mbar
0 5 10 15 20 250
25
50
75
100
125
150
175
- V
dc (
V)
Weff
(W)
N2N21 mbar0.5 mbar0.2 mbar
1 mbar0.5 mbar0.2 mbar
0 5 10 15 20 250
25
50
75
100
125
150
175
- V
dc (
V)
Weff
(W)
N21 mbar0.5 mbar0.2 mbar
Modelling & simulationCapacitively coupled radio-frequency discharges
Very complete state-of-the-art kinetic schemes
0.8 1.0 1.2 1.4 1.60.0
0.5
1.0
1.5
2.0
2.5
Inte
nsity
(a.
u.)
Z (cm)
Model Exp. 777.194 nm 777.417 nm 777.539 nm
0.8 1.0 1.2 1.4 1.60.0
0.5
1.0
1.5
2.0
2.5
Inte
nsity
(a.
u.)
Z (cm)
Model Exp. 777.194 nm 777.417 nm 777.539 nm
0.8 1.0 1.2 1.4 1.60
1
2
3
4
Inte
nsity
(a.
u.)
Z (cm)
Model Exp. 742.364 nm 744.229 nm 746.831 nm
0.8 1.0 1.2 1.4 1.60
1
2
3
4
Inte
nsity
(a.
u.)
Z (cm)
Model Exp. 742.364 nm 744.229 nm 746.831 nm
80 90 100 110 120 130
1010
1011
1012
N2
+(B)
N2(C)
Den
sity
(cm
-3)
Pcoup
(W)80 90 100 110 120 130
1010
1011
1012
N2
+(B)
N2(C)
Den
sity
(cm
-3)
Pcoup
(W)
Very good agreement with OES diagnosticsN2(C) & N2
+(B) absolute densities
O* triplet (left) andN* triplet (right)
Modelling & simulationKinetic modelling of air plasmas in capillaries at low pressure
Modelling & simulationPlasma conversion of CH and CO
Natural gas is still an abundant chemical source
Goal: production of H2, Syngas and methanol
Challenges: Energy efficiency!
Modelling and experimental work @ patm
Modelling & simulationSurface kinetics
Molecule formation on surfaces is a relevant issue!
O2, N2, NO, NO2, O3, CO2 ...
Major difficulties:- Good control of surface conditions
- Reproducibility
- “Unambiguous” interpretation
NO conversion into NO2 in a Pyrex tube. NO is introduced in successive injections in a tube pre-treated with oxygen.
Modelling & simulationKinetics of high-speed shock flows and radiative heat-transfer studies
Ray tracing procedureCFD/state-to-state simulation of 12km/s entry flow
Complete cross section sets: Ar, He, H2 / H, N2 / N, O2, CH4
Experimental swarm data
Check agreement between calculated and measured swarm datafrom different databases
http://fr.lxcat.net/
Modelling & simulationLXCat website and IST-LISBON database
Hypersonic Plasma Laboratory
Hypersonic Plasma LaboratoryEuropean Shock-tube for High Enthalpy Research (ESTHER)
Final
Plasma …
• cold present in everyday life
• base for multiple applications(quality-of-live improvement)
• solution for energetic problems(check previous presentations)
• beautiful medium
APPLAuSEAdvanced Programme in Plasma Science and Engineering
Next call: April-June 2015https://applausephd.wordpress.com/
