Identification of nitrogen chemical states in N-doped ZnO via x-ray photoelectron spectroscopy

Journal Article · Tue Feb 01 04:00:00 EST 2005 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1847728· OSTI ID:20665105

Perkins, Craig L; Lee, Se-Hee; Xiaonan, Li; Asher, Sally E; Coutts, Timothy J ^[1]

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1. National Renewable Energy Laboratory, 1617 Cole Boulevard, MS 3215, Golden, Colorado 80401 (United States)

Nitrogen-doped films of ZnO grown by two methods, metalorganic chemical vapor deposition (MOCVD) and reactive sputtering, were studied with x-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). Systematic differences in the N chemical states were observed between films grown by sputtering and MOCVD: only two N chemical states were observed in films grown by reactive sputtering, whereas four N chemical states were observed in MOCVD films. To aid in the assignment of the N chemical states, photoemission data from the polycrystalline films were compared with data taken on N{sub 2}{sup +}-implanted Zn metal and N{sub 2}{sup +}-implanted ZnO. High-resolution core level spectra of the N 1s region indicated that nitrogen can occupy at least four different chemical environments in ZnO; these include the N{sub O} acceptor, the double donor (N{sub 2}){sub O}, and two carbon-nitrogen species. Valence band spectra indicate that the Fermi energy of all films studied was near the conduction band minimum, implying that the films remained n-type after nitrogen doping. Analysis of the relative amounts of acceptors and donors identified by XPS in the sputter-grown films provides clues as to why only a small percentage of incorporated nitrogen is found to contribute to carriers, and points toward possible paths to higher quality ZnO:N films.

• OSTI ID: 20665105
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 97; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
BINDING ENERGY
CARBON
CHEMICAL STATE
CHEMICAL VAPOR DEPOSITION
CRYSTAL GROWTH
DOPED MATERIALS
FERMI LEVEL
NITROGEN
PHOTOEMISSION
POLYCRYSTALS
RESOLUTION
SEMICONDUCTOR MATERIALS
SPUTTERING
THIN FILMS
ULTRAVIOLET SPECTRA
VALENCE
X-RAY PHOTOELECTRON SPECTROSCOPY
ZINC
ZINC OXIDES