Direct observation of nitrogen location in molecular beam epitaxy grown nitrogen-doped ZnO

作者：Fons P^*; Tampo H; Kolobov **; Ohkubo M; Niki S; Tominaga J; Carboni R; Boscherini F; Friedrich S

来源：Physical Review Letters, 2006, 96(4): 045504.

DOI：10.1103/PhysRevLett.96.045504

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.

• 出版日期2006-2-3