Ultraviolet surface plasmon-mediated low temperature hydrazine decomposition

Journal Article · Mon Jan 12 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4905593· OSTI ID:22399122

Peng, Siying; Sheldon, Matthew T.; Atwater, Harry A. ^[1]; Liu, Wei-Guang; Jaramillo-Botero, Andres; Goddard, William Andrew ^[2]

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1. Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States)
2. Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 (United States)

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{sub 2}H{sub 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{sub 2}H{sub 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.

• OSTI ID: 22399122
• Journal Information: Applied Physics Letters, Vol. 106, Issue 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM
COMPARATIVE EVALUATIONS
CONCENTRATION RATIO
DEPOSITION
DISSOCIATION
EV RANGE
HYDRAZINE
HYDROGEN
KRYPTON FLUORIDE LASERS
MASS SPECTROSCOPY
MOLECULES
NANOSTRUCTURES
NITROGEN
PHOTOLYSIS
PLASMONS
PRECURSOR
SUBSTRATES
SURFACES
THIN FILMS
ULTRAVIOLET RADIATION