Imaging of electrical response of NiO_x under controlled environment with sub-25-nm resolution

Journal Article · Tue Jul 19 00:00:00 EDT 2016 · Journal of Photonics for Energy

DOI:https://doi.org/10.1117/1.JPE.6.038001· OSTI ID:1295116

Jacobs, Christopher B. ^[1]; Ievlev, Anton V. ^[1]; Collins, Liam F. ^[1]; Muckley, Eric S. ^[1]; Joshi, Pooran C. ^[2]; Ivanov, Ilia N. ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Div.

The spatially resolved electrical response of rf-sputtered polycrystalline NiO_x films composed of 40 nm crystallites was investigated under different relative humidity levels (RH). The topological and electrical properties (surface potential and resistance) were characterized using Kelvin probe force microscopy (KPFM) and conductive scanning probe microscopy at 0%, 50%, and 80% relative humidity with sub 25nm resolution. The surface potential of NiO_x decreased by about 180 mV and resistance decreased in a nonlinear fashion by about 2 G when relative humidity was increased from 0% to 80%. The dimensionality of surface features obtained through autocorrelation analysis of topological, surface potential and resistance maps increased linearly with increased relative humidity as water was adsorbed onto the film surface. Spatially resolved surface potential and resistance of the NiO_x films were found to be heterogeneous, with distinct features that grew in size from about 60 nm to 175 nm between 0% and 80% RH levels, respectively. Here, we find that the changes in the heterogeneous character of the NiO films are consistent through the topological, surface potential, and resistance measurements, suggesting that the nanoscale surface potential and resistance properties converge with the mesoscale properties as water is adsorbed onto the NiO_x film.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC)
• Grant/Contract Number: AC05-00OR22725; CPS 24762; CPS 24764
• OSTI ID: 1295116
• Journal Information: Journal of Photonics for Energy, Vol. 6, Issue 3; ISSN 1947-7988
• Publisher: SPIE
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
nickel oxide
humidity
local conductivity
KPFM
conductive AFM