Ultraviolet surface plasmon-mediated low temperature hydrazine decomposition
Abstract
Conventional methods require elevated temperatures in order to dissociate high-energy nitrogen bonds in precursor molecules such as ammonia or hydrazine used for nitride film growth. We report enhanced photodissociation of surface-absorbed hydrazine (N_2H_4) molecules at low temperature by using ultraviolet surface plasmons to concentrate the exciting radiation. Plasmonic nanostructured aluminum substrates were designed to provide resonant near field concentration at λ = 248 nm (5 eV), corresponding to the maximum optical cross section for hydrogen abstraction from N_2H_4. We employed nanoimprint lithography to fabricate 1 mm × 1 mm arrays of the resonant plasmonic structures, and ultraviolet reflectance spectroscopy confirmed resonant extinction at 248 nm. Hydrazine was cryogenically adsorbed to the plasmonic substrate in a low-pressure ambient, and 5 eV surface plasmons were resonantly excited using a pulsed KrF laser. Mass spectrometry was used to characterize the photodissociation products and indicated a 6.2× overall enhancement in photodissociation yield for hydrazine adsorbed on plasmonic substrates compared with control substrates. The ultraviolet surface plasmon enhanced photodissociation demonstrated here may provide a valuable method to generate reactive precursors for deposition of nitride thin film materials at low temperatures.
Additional Information
© 2015 AIP Publishing LLC. Received 27 August 2014; accepted 26 December 2014; published online 12 January 2015. This work was supported by DARPA under Grant No. W911NF-13-1-0040 and utilized facilities of the Kavli Nanoscience Institute at Caltech.Attached Files
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Additional details
- Eprint ID
- 53878
- Resolver ID
- CaltechAUTHORS:20150120-114536870
- Army Research Office (ARO)
- W911NF-13-1-0040
- Defense Advanced Research Projects Agency (DARPA)
- Created
-
2015-01-20Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute
- Other Numbering System Name
- WAG
- Other Numbering System Identifier
- 1151