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Author Kumar, Mohit ♦ Basu, Tanmoy ♦ Som, Tapobrata
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ATOMIC FORCE MICROSCOPY ♦ CHARGE TRANSPORT ♦ DOPED MATERIALS ♦ ELECTRIC FIELDS ♦ FILMS ♦ GRAIN BOUNDARIES ♦ NANOSTRUCTURES ♦ POLARIZATION ♦ SILICON OXIDES ♦ SUBSTRATES ♦ TITANIUM OXIDES ♦ ZINC OXIDES
Abstract In this paper, based on piezoforce measurements, we show the presence of opposite polarization at grains and grain boundaries of Al-doped ZnO (AZO). The polarization can be flipped by 180° in phase by switching the polarity of the applied electric field, revealing the existence of nanoscale pseudoferroelectricity in AZO grown on Pt/TiO{sub 2}/SiO{sub 2}/Si substrate. We also demonstrate an experimental evidence on local band bending at grain boundaries of AZO films using conductive atomic force microscopy and Kelvin probe force microscopy. The presence of an opposite polarization at grains and grain boundaries gives rise to a polarization-driven barrier formation at grain boundaries. With the help of conductive atomic force microscopy, we show that the polarization-driven barrier along with the defect-induced electrostatic potential barrier account for the measured local band bending at grain boundaries. The present study opens a new avenue to understand the charge transport in light of both polarization and electrostatic effects.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-01-07
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 119
Issue Number 1


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