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

Abstract

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.

Molecular nitrogen acceptors in ZnO nanowires induced by nitrogen plasma annealing

“…No changes in the nanowire morphology were detected after plasma annealing. The XANES spectra of N-doped nanowires could be deconvoluted into three Lorentzian peaks to represent resonant electron transitions from the N 1s initial state to the final unoccupied N-related state of p symmetry [11], after subtracting an arctangent step function that represents the transition of ejected photoelectrons to the continuum [16]. Examples of the peak deconvolution are shown in Figs.…”

Synthesis and Characterization of Nitrogen‐Doped Group IVB Visible‐Light‐Photoactive Metal Oxide Nanoparticles

“…[1][2][3] Among the main group elements, nitrogen is believed to be the most favorable p-type dopant because of its similar size to oxygen, metastable AX center formation, and small ionization energy.[4] For example, the incorporation of N into ZnO has been found to be a very promising way to make p-type ZnO, which represents a potentially useful alternative to toxic and expensive III-V semiconductors for applications such as light-emitting devices (LEDs). [2,5,6] Another exciting example is visible-light-active TiO 2 , which is a promising material for applications such as water splitting and photocatalysis.…”

“…[1][2][3] Among the main group elements, nitrogen is believed to be the most favorable p-type dopant because of its similar size to oxygen, metastable AX center formation, and small ionization energy.…”

Nitrogen deep accepters in ZnO nanowires induced by ammonia plasma

“…[5][6][7][8][9][10][11][12][13] Among them, nitrogen has been considered as a promising p-type dopant of ZnO because of its similar ionic radius to oxygen. 14 Although nitrogen incorporation in ZnO has been intensively investigated experimentally and theoretically, the progress along this direction is slow, and nitrogen doping mechanisms and modes [15][16][17][18][19] are still controversial.…”