Transcript Badami_Pranav_sol_new _sm

MOCVD Grown GaN/AlGaN
Quantum Cascade Detectors
Pranav Badami,1 Yu Song,1 Chung-En Zah2,
Rajaram Bhat2, Claire F. Gmachl1
1 – Princeton University, Princeton, NJ 08544, USA
2 – Corning Incorporated, Corning, NY 14831, USA
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Internship Information
• Mid-Infrared Technologies for Health and
Environment: Princeton, NJ
• Trace Gas Detection
*
GAS
(>
Quantum Cascade Detector
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Environmental Applications
http://kassowal.com/wallpaper/Animal-wallpaper/Cow/2.jpg
http://csmres.co.uk/cs.public.upd/article-images/Oil-rig2.jpg
Applications:
- Greenhouse gas sensing
- Methane leaks
- Farm monitoring
http://www.junksciencearchive.com/Greenhouse/
Challenges
• Methane absorbs 3.2 micron
• Requires new material system –
– GaN/AlGaN
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GaN / AlGaN QCD
Necessities:
• Scalable production
• Low-wavelength detection
• High-speed detection
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Improvements
Metal Organic Chemical Vapor Deposition
(MOCVD)
GaN : large conduction band offset
AlGaN : reduced scattering lifetime
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Fabrication and Testing
- Many hours in the cleanroom
- Processed detector device with windows
on top
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Results and Measurements
Photocurrent
Spectrum
Noise
-9
Dark Current Noise (A/ÖHz)
Photocurrent (arbitrary units)
15
max photocurrent at ~ 4.3 um
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0V
Smoothed 0V
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0
2
4
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Wavelength (m)
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240 K
10
300 K
200 K
-10
10
160 K
120 K
-11
10
80 K
-12
10
-13
10
0.01
0.1
1
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Applied Bias (V)
- Low noise and photocurrent for short wavelengths.
- First of it’s kind to be commercially viable!
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Acknowledgements and Future
Plans
Summary: First MOCVD grown GaN/AlGaN quantum
detector
Skills: presented work, coauthored conference paper
ITQW 2013, Cleanroom, presentation, semiconductors
Thank you to the PEI Grand Challenges
program for the opportunity and funding.
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