atomic layer deposition of zirconium oxide for fuel cell applications uic reu – summer 2011 amrel...
TRANSCRIPT
![Page 1: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/1.jpg)
Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications
UIC REU – Summer 2011AMReL Lab, UIC
Department of Bioengineering andDepartment of Chemical Engineering
Christine JamesUniversity of Michigan, Department of Chemical Engineering
![Page 2: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/2.jpg)
Overview
• Background• Atomic Layer Deposition• Data Collected• Future Work
![Page 3: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/3.jpg)
Fuel Cell Advantages
• Provides clean energy– Hydrogen fuel cells – only emit water
• Very efficient– Fuel Values
• Hydrogen: 141.8 kJ/g• Gasoline: 48 kJ/g • Coal: 15-27 kJ/g
Santhanam et al., Introduction to Hydrogen Technology, 2009, Hoboken, NJ: J. Wiley.
Fossil fuel
2007
Environmentally friendly
Coal 23 %
Nuclear Power 8 %
Renewable Energy 6 %
Petroleum 40 %
Natural Gas 23 %
Source: US Energy Information Agency
![Page 4: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/4.jpg)
Sections of the Fuel Cell
• Cathode– Oxygen is reduced
• Anode– Hydrogen is oxidized
• Electrolyte– Transports the oxygen ions
www1.eere.energy.gov
SOFC FUEL CELL
Fuel In Air In
Unused Gases Out
Excess Fuel and
Water
Electrical Current
![Page 5: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/5.jpg)
Solid Oxide Fuel Cells (SOFCs)• Current SOFCs are high temperature– Temperature: about 1000 °C
• Intermediate Temperature Fuel Cells– Temperature: 600-800°C– Smaller scale applications– Allows use of alternate materials– Starts and stops faster– Reduces corrosion – Offers a wide range of possibilities
![Page 6: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/6.jpg)
Problem with Reducing Temperature• High temperatures needed to transport O2- ions – Requirement can be as high as 1200° C– Low temperatures cause ionic resistance
• Deposit electrolytes and analyze– Samples from atomic to bulk-like thickness– Method to be used:
• Atomic Layer Deposition
• Deposit oxide layers on silicon then platinum (Pt)
Approach
![Page 7: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/7.jpg)
Atomic Layer Deposition (ALD)
www.cambridgenanotech.com/ald
H2O
Tri-methyl aluminumAl(CH3)3(g)
Methyl group(CH3)3(g)
Hydroxyl (OH) from surface absorbed H2O
Reaction of TMA with OH
Methane reaction product CH4
![Page 8: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/8.jpg)
Chosen Precursor
www.aloha.airliquide.com
Niinistö, et al., Advanced Engineering Materials, 2009, 11, No.4, 223.
Precursors Growth Temperature ImpuritiesMetal Precursor O source Range (°C) Preferred (°C) Saturation verified C [-at%] H [-at%]
at 300 °C ZyALD Ozone 250-400 300 Yes <1 N.R.
![Page 9: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/9.jpg)
ALD System
ZyALD
ZyALD
![Page 10: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/10.jpg)
Pulse and Purge times requiredReactor Temperature: 300°CBubbler Temperature: 50°CBubbler Pressure: 10 torrPrecursor: ZyALDPrecursor Pulse Time:
Precursor Purge Time:Oxidizer Pulse Time:Oxidizer Purge Time:Run for 40 cycles
Varied6 s
20 sVaried1.5 s
Varied
2 2.5 3 3.5 4 4.5 5 5.5 6 6.50.4
0.5
0.6
0.7
0.8
0.9
1
Precursor Pulse Time (s)
Gro
wth
Rat
e (Å
/cyc
le)
2 4 6 8 10 12 140.700000000000001
0.750000000000001
0.800000000000001
0.850000000000001
0.900000000000001
0.950000000000001
1
Precursor Purge Time (s)
Grow
th R
ate
(Å/c
ycle
)
10 s
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.80.600000000000001
0.650000000000001
0.700000000000001
0.750000000000001
0.800000000000001
0.850000000000001
0.900000000000001
0.950000000000001
1
Oxidizer Pulse Time (s)
Gro
wth
Rat
e (Å
/cyc
le)
12 13 14 15 16 17 180.600000000000001
0.650000000000001
0.700000000000001
0.750000000000001
0.800000000000001
0.850000000000001
0.900000000000001
0.950000000000001
1
Oxidizer Purge Time (s)
Gro
wth
Rat
e (Å
/cyc
le)
17 s
1 s
Varied
Zr
www.cambridgenanotech.com/ald
![Page 11: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/11.jpg)
Temperature WindowReactor Temperature: VariedBubbler Temperature: 50°C
Bubbler Pressure: 10 torrPrecursor: ZyALD
50 100 150 200 250 300 350 4000
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Temperature (°C)
Gro
wth
Rat
e (Å
/cyc
le)
Precursor Condensation Precursor Decomposition
Temperature Window
![Page 12: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/12.jpg)
Comparison to Work from another group
225 250 275 300 325 3500
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Temperature (°C)
Gro
wth
Rat
e (Å
/cyc
le)
Niinistö, et al., J. Mater. Chem. 18, 5243 (2008).
![Page 13: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/13.jpg)
Thickness vs. Cycles RunReactor Temperature: 300°CBubbler Temperature: 50°C
Bubbler Pressure: 10 torrPrecursor: ZyALD
0 20 40 60 80 100 120 140 160 1800
20
40
60
80
100
120
140
160
Number of Cycles Run
Thic
knes
s (Å
) Slope: .87R² = 0.9973
![Page 14: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/14.jpg)
Future Work
1. Deposit the zirconium oxide on Platinum2. Run electrochemical analysis
Silicon Substrate
Electrolyte: Zirconium Oxide
Platinum
![Page 15: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/15.jpg)
Summary• Goal is to lower operating temperature of the fuel cell– By decreasing electrolyte layer thickness
• Atomic Layer Deposition (ALD) is being used• Have determined some necessary parameters:– Pulse and Purge times– Temperature Window for ALD
• Have compared cycles and thickness– Proved linear relationship
• Next Steps: – Deposit on Platinum – Run Electrochemical analysis
![Page 16: Atomic Layer Deposition of Zirconium Oxide for Fuel Cell Applications UIC REU – Summer 2011 AMReL Lab, UIC Department of Bioengineering and Department](https://reader036.vdocuments.net/reader036/viewer/2022062318/551c54db550346a5458b4ef0/html5/thumbnails/16.jpg)
Acknowledgements
• National Science Foundation– EEC-NSF Grant # 1062943
• Graduate Mentor: Runshen Xu• Professor Takoudis and Professor Jursich