Direct Observation of Nitrogen Location in Molecular Beam Epitaxy Grown Nitrogen-Doped ZnO

Journal Article · Fri Feb 02 04:00:00 EST 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2644531· OSTI ID:21054632

Fons, P; Tampo, H; Kolobov, A V; Ohkubo, M; Niki, S; Tominaga, J ^[1]; Carboni, R ^[2]; Friedrich, S ^[3]

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1. National Institute of Advanced Industrial Science and Technology, Tsukuba Central 4, Higashi 1-1-1, Tsukuba, Ibaraki, 305-8562 (Japan)
2. Physics Department, University of Bologna, viale C. Berti Pichat 6/2, 40127 Bologna (Italy)
3. Advanced Detector Group, L-270 Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

ZnO is a wide band gap, naturally n-type semiconductor with great promise for optoelectronic applications. To date, however, it has proven difficult to dope p-type, a prerequisite for device fabrication. Nitrogen is widely believed to be one of the most promising dopant candidates, however, experimental results to date have been inconsistent; recent theoretical formation energy calculations have indicated that Nitrogen preferentially incorporates into the ZnO lattice in the form of a N{sub 2}{sup -} molecule at an O-site when a Nitrogen plasma source is used, leading to compensation rather than p-type doping. We show by a combination of X-ray absorption spectroscopy at the N K-edge of plasma-assisted molecular beam epitaxy grown ZnO and ab-initio simulations that in as-grown material, Nitrogen incorporates substitutionally on an O-site where it is expected to act as an acceptor. We have also observed the distinctive formation of molecular nitrogen bubbles upon rapid thermal annealing. These results suggest that effective p-type doping of ZnO with N may only be possible for metastable low-temperature growth processes.

• OSTI ID: 21054632
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 882; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ANNEALING
COMPUTERIZED SIMULATION
CRYSTAL DOPING
DOPED MATERIALS
FORMATION HEAT
LAYERS
MOLECULAR BEAM EPITAXY
MOLECULES
NITROGEN
P-TYPE CONDUCTORS
X-RAY SPECTRA
X-RAY SPECTROSCOPY
ZINC OXIDES