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TRANSCRIPT
Thin Film Solutions
01-2010
Bulk and
special gas
distribution
Chemical supply
systems
Process vacuum
and exhaust systems
Portfolio
Engineering,
design and
development
Service and
operation
Global Structure
14.09.2012 3
AMERICAS
Sales and Project Execution
EUROPE
HQ, R&D, Manufacturing Dresden GER Service Hub Erfurt GER
ASIA PACIFIC
Service Hub and SalesGreater China, South East Asia Taiwan
Trading Partners Japan, Korea
Thin-Film Solutions
• HiBarSens
• Special equipment for thin film deposition (excerpt…)– DEZn supply for ZnO TCO layers– TMAl supply for AlOx backside passivation– PECVD for barrier layers – HMDSO…– Enabling III/V on Si– Special liquid Indium-MO source
supply systems for IGZO– LED supply systems for MO-III (TMGa)– ….
14.09.2012 4
Water Vapor
Permeation
Measurement System
Food industry
Pharmaceutical industry
Anorganic solar cells
Organic solar cells
Vacuum isolation paneele
Organic LED
10-0
10-3
10-61E-6
1E-5
1E-4
1E-3
0,01
0,1
1
10
Wat
er tr
ansm
issi
on ra
te W
VTR
g[H
2O] m
-2d-
1
Summary: Starting point
currentlymeasurable
bystandardmethods
?
WVTR of 10x g m-2 d-1 is equivalent to:
10-7 10-6 10-5 10-4 10-3 10-2 10-1 100 101 102 103 104
… per day!
One water drop …… at a sample area of:
WVTR
???
Vatican City
Tennis court
Dresden Zwinger + park
Soccer fieldPing-pong table
Chessboard
Beer coaster
Crown cork
Confetti Industry standard (MOCON)
Market forecast for ultra barrier films
0
0.5
1
1.5
2
2.5
3
3.5
4Bi
llion
US$
Year
Photovoltaics
Electrophoretic*
OLED light*
OLED Billboard etc*
OLED display*
Harry Zervos: "Barrier Films for Flexible Electronics: Needs, Players &Opportunities". IDTechEx Ltd., December 2008)
HiBarSens
• HiBarSens Basics
BASICS
n Measuring setup: dynamic (isostatic) static (quasi isostatic)
n Typical chart
n Calculation of WVTR
Measuring modes: dynamic vs. static
ϕϕ−
⋅⋅⋅⋅⋅
=1
2 pATRMV
WVTRsample
OHPurge&
tp
AM
TRVnWVTR
sample
OHcellsorp ∆
∆⋅⋅⋅
⋅=−
ϕ2&
Sample 1
Sample 2
10-4
10-3
10-2
10-1
Wat
er v
apor
mas
s flu
x j
/ g
m-2
d-1
Time t / h
Wat
er v
apor
vol
ume
fract
ion
ϕ / p
pm
Time t / h
WVTR
WVTR
ϕ … Water vapor volume fraction (measured by LDS)
n Tunable diode laser absorption spectroscopy (TDLAS)
Limit of Detection LOD(H2O):
n Measuring setup:
n Sample size
n Chamber volume
n Accumulation time
n Purge flow
n Optical path length
n WVTR < 10-4 g m-2 d-1
are measurable
100 ppb m
The LASER as a sensor
100 cm2
0,1 l
- 10 h
0,01 slm -
1 m
~ 10-6 g m-2 d-1~ 10-5 g m-2 d-1
dynamic static
!Theoretical estimations!
Balance equation for dynamic
n = amount of substance (moisture)
n
cell
sample
Adsorption isotherm
Steady-state conditions
ϕϕ−
⋅⋅⋅⋅⋅
=1
2 pATRMV
WVTRSample
OHPurge&
nsorption@cell•
nsorption@sample•
nout•
Nadsorp
pH2O
10-4
10-3
10-2
10-1
Mas
s flu
x j H
2O /
g m
-2 d-1
Time t / h
Sample 1
Sample 2
General balance equation
Vpurge; nin• •
Calculation of WVTR
( ) .0
0
0
0
consttnnnnpp
nnn
outperm
adsorptiondesorptionsorption
=∆⋅−=−=−
=−=
&&
&&&
( ) ooutleaksorptpermin ntnnnnnn +∆⋅−+++= &&&&&
( ) ooutperm ntnnn +∆⋅−= &&
npermeation•
Balance equation for static setup
( ) osorptperm ntnnn +∆⋅+= &&
0;0
;0
0 >−>−=
===
ppnnnconstnnn
desorptionadsorptionsorption
permoutin
&&&
&&&
Adsorption isotherm
Nadsorp
pH2O
cell
sample
n = amount of substance (moisture)
nnsorption@cell•
npermeation•
nsorption@sample•
( ) ooutleaksorptpermin ntnnnnnn +∆⋅−+++= &&&&&
General balance equation
„non constant“ conditions
tp
AM
TRVWVTR
AM
tn
AM
nWVTR
Sample
OHcell
Sample
OH
Sample
OHperm
∆∆⋅
⋅⋅⋅
=
⋅∆∆
==
ϕ2
22&
tp
AM
TRVnWVTR
Sample
OHcellsorp ∆
∆⋅⋅⋅
⋅=−
ϕ2&
Calculation of WVTRnout•
nin•
Wat
er v
apor
vol
ume
fract
ion
ϕ / p
pm
Time t / h
00 24 48 72 96
0
1
2
3
4 GRA, Quasi-isostatisch_neu_GM_12_06_07, 4.7.2012
Time t / hh
Wat
er v
apor
vol
ume
frac
tion
ϕ /
ppm
Static measurement: Background level
purge quasi isostatic measurement
Measured background level (sample: stainless steel)
@ 38°C / 90% r.H.WVTRqis = 2,5 x 10-6 g m-2 d-1
00 24 48 72 96
0
1
2
3
4 GRA, Quasi-isostatisch_neu_GM_12_06_07, 4.7.2012
Time t / hh
Wat
er v
apor
vol
ume
frac
tion
ϕ /
ppm
Dynamic vs. Static: background level
Measured background level (sample: stainless steel) @ 38°C / 90% r. H.
WVTRqis = 2,5x 10-6 g m-2 d-1
Dynamic setup Static setup
010 020 030 040 050
10-5
10-4
10-3
10-2 SCHA, H2O_Konzmessung_Leermessung_isostatisch, 4.7.2012
Time t / DDD
Wat
er v
apor
mas
s vel
ocity
/ g
m-2 d
-1
WVTRqis = 5x 10-5 g m-2 d-1
PPRODUCTIMPLEMENTATION
HiBarSens
Sensitivity of a WVTR measurement
N2H2O
N2 + H2O
Sealing of the test cell
Sensor sensitivity
Adsorption / desorption of moisture
Parameters for tuning the sensitivity
LOD = 150 ppb mTheoretical sensitivity
N2H2O
N2 + H2O
dcIIo
⋅⋅=− λελλ
)()(ln
c
dynamic setup
• Optical path length• Carrier gas flow à c• Sample area à c• Selection of absorption line
Tuning sensitivity: optical path length
Multipath design in HiBarSens®
2 m optical path length by multi 20 reflections
Tuning sensitivity: Carrier gas flow
02 24 240
10-4
10-3
10-2
10-1
100
0
10
20
30
40
50
60
WVTR
Purg
e flo
w V
* / s
ccm
WVT
R /
g[H
2O] m
-2d-1
Time t / hours
Purge gas flow
Carrier gas flow 3 sccm - 50 sccm
Boost the sensitivity by factor 16!
Sensitivity of WVTR measurement
Sensor sensitivity: the laser as a sensor
n High dynamic range: ppb - % (10-5 – 1 g m-2 d-1)n Very high selectivityn Immune to high concentrated moisturen Long time stable, no drift, no hysteresisn Low-maintenancen Change of target permeate by change of the laser
dioden Allows the realization of a compact designn Easy to use
Further advantages
Tunable Diode Absorption Spectroscopy (TDLAS) is a non-invasive, high sensitive, high selective sensor for detection of moisture traces!
Sensitivity of WVTR measurement
Adsorption / desorption of moisture
N2H2O
N2 + H2O
10-4
10-3
10-2
10-1M
ass
flux
j H2O
/ g
m-2
d-1
Time t / h
jcell = jsample = jtubes = 0
jsystem = WVTR (δj/δt = 0)
Sample 1
Sample 2
Mass flux [ ][ ]dtmA
gmdm
gj
jjjWVTRj
x
OHx
tubessamplecellsystem
∆⋅
∆=
⋅
+++=
²][2
2
Sensitivity of WVTR measurement
Adsorption / desorption of moisture
N2H2O
N2 + H2O
n Steady state conditions are requiredn As small as possible surface area of the cell
in contact with moisturen Ultra smooth surfacesn Avoid any problematic materials inside the
celln Highest temperature stabilityn HiBarSens - realization n Volume and surface vs. sample area
optimized cell designn Electro-polished surfacesn Temperature stability < 0,5°Cn Sensor is placed inside the test cell
Sensitivity of WVTR measurement
Sealing of test (measuring) cell
n Sample clamping has to follow the requirement for leakage rates of 2.4E-9 mbar*l/sn Substitution of the classical concept
(polymer O-rings) by the concept of an “active sealing”
n Purge channels prevent ambient moisture diffusion into the cell
Mass flux: leakagecellsystem jjWVTRj +++= ...
HiBarSens® at work
0 10 20 30 40 5010-5
10-4
10-3
10-2
Time t / d
Mass f lux (H2O) / g m-2 d-1
5 x 10-5 g m-2 d-1
Measured background level
(sample: stainless steel)
00:00 24:00 48:00 72:00 96:00 120:00 144:00 168:0010-4
10-3
10-2
10-1 WVTR / g m-2 d-1
Time t / h
Adjusting the gas flow
4,1 x 10-4 g m-2 d-1
WVTR-measurement
of ultra barrier sample
(Fraunhofer POLO)
3,12 3,14 3,16 3,18 3,20 3,22 3,24 3,26 3,28 3,30
-8,4
-8,0
-7,6
-7,2
1000/Temperature / K-1
ln(WVTR / g m-2 d-1) (@ 85 % RH)
Temperature dependence of ultra barrier sample
(for photovoltaic)
Measurement
compact & easy to use device
Rel. Humidity controller
Sample
Flow controller
N2 purge gas in /out
Permeation cell- tempered- integrated moisture generator- Gentle clamping of
the test sample
Purifier valve
Place sample
Close test cell
Adjust rel. Humiditypurge flow, temperature
Print report
Connectors for thermostat
Summary
n HiBarSens laser based sensor technology for highly sensitive determination of water vapor transmission rates of ultra barrier samples
n HiBarSens provides reliable measurements of WVTR down to 10-5 g m-2 d-1 with the potential to 10-6 g m-2 d-1
n HiBarSens is available as a compact, easy to use table top device
Acknowlegment
Johannes Grübler
Kurt Pietsch
Harald Beese
Wulf Grählert
responsible for manufacturing and sales