Direct observation of nitrogen location in molecular beam epitaxy grown nitrogen-doped ZnO.
Direct observation of nitrogen location in molecular beam epitaxy grown nitrogen-doped ZnO.
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DOI:
10.1063/1.2644531
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发表时间:
2006-02
影响因子:
8.6
通讯作者:
P. Fons;H. Tampo;A. Kolobov;M. Ohkubo;S. Niki;J. Tominaga;R. Carboni;F. Boscherini;S. Friedrich
中科院分区:
文献类型:
--
作者:
P. Fons;H. Tampo;A. Kolobov;M. Ohkubo;S. Niki;J. Tominaga;R. Carboni;F. Boscherini;S. Friedrich
ZnO is a wide band gap, naturally n-type semiconductor with great promise for optoelectronic applications; the main obstacle yet to be overcome is p-type doping. Nitrogen, the most promising candidate currently being pursued as a dopant, has been predicted to preferentially incorporate into the ZnO lattice in the form of a N-2 molecule at an O site when a plasma source is used, leading to compensation rather than p-type doping. We demonstrate this to be incorrect by using N K-edge x-ray absorption spectra and comparing them with first-principles calculations showing that nitrogen, in fact, incorporates substitutionally at O sites where it is expected to act as an acceptor. We also detect the formation of molecular nitrogen upon annealing. These results suggest that effective p-type doping of ZnO with N may be possible only for low-temperature growth processes.