Nitrogen doping on NiO by reactive magnetron sputtering: A new pathway to dynamically tune the optical and electrical propertiesShow others and affiliations
2017 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 409, p. 77-84Article in journal (Refereed) Published
Abstract [en]
N-doped nickel oxide (NiO:N) thin films were deposited on glass and silicon substrates by reactive DC magnetron sputtering in Ar/O-2/N-2 gas atmosphere with a series of N-2/O-2 gas ratio ranging from 0 to 80%. X-ray diffraction measurements have revealed that the films are constituted of Ni1_xO grains and showed enhanced polycrystalline features with increasing N-doping concentration. For the first time, we report here that N-doping in the Ni-deficient NiO (Ni1-xO) film leads to a band-gap narrowing from 3.6 to 2.3 eV. X-ray photoelectron spectroscopy (XPS) measurements proved that up to 4 atomic percent (at.%) nitrogen can be incorporated at least at the surface of the NiO:N samples. In addition, XPS valence band spectra and UV-vis transmission measurements have demonstrated that the band-gap narrowing may originates from the contribution of an intermediate band (IB) similar to 2.4 eV just above the valence band maximum and the up-shifting of the valence band edge (similar to 0.3 eV) due to the introduction of occupied N 2p states. Local I-V measurements, carried out by conductive AFM (C-AFM), have revealed that the extrinsic doping of N atoms within the oxide can be a good way to precisely control the electrical conductivity of such p-type materials. (C) 2017 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV , 2017. Vol. 409, p. 77-84
Keyword [en]
Nitrogen doping; Nickel oxide; Reactive sputtering; XPS; Optical band-gap; C-AFM
National Category
Materials Chemistry
Identifiers
URN: urn:nbn:se:liu:diva-137583DOI: 10.1016/j.apsusc.2017.02.229ISI: 000400223900012OAI: oai:DiVA.org:liu-137583DiVA, id: diva2:1097522
Note
Funding Agencies|Institut de Recherche Technologique (IRT) Jules-Verne
2017-05-222017-05-222017-05-22