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An extended grain boundary barrier height model including the impact of internal electric field

Xu, Bai-Xiang and Zhou, Ziqi and Keil, Peter and Frömling, Till (2018):
An extended grain boundary barrier height model including the impact of internal electric field.
In: AIP Advances, AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA, pp. 1-9, 8, (115126), ISSN 2158-3226, DOI: 10.1063/1.5049473, [Article]

Abstract

An extended phenomenological model is proposed to rationalize the potential barriers of the varistor like boundaries of piezoelectric semiconductors. This model takes selfconsistently into account the inverse piezoelectric effect of the internal electric field associated with the barrier height at grain boundaries. A double Schottky barrier at a grain boundary gives rise to a strong internal electric field in the depletion layer. Due to the inverse piezoelectric effect, this internal electric field leads to mechanical strain and consequently piezoelectric charge at a grain boundary and also an additional space charge associated with the polarization inhomogeneity. The piezoelectric charges in return impacts the barrier height. Results show that the piezoelectric charge induced by the internal field tends to adjust the grain boundary charge and lowers the barrier height. Furthermore, the barrier height becomes less sensitive to mechanical stress and applied voltage if the influence of the internal field is taken into account. The extended model with the inverse piezoelectric effect of the internal field allows to further elucidate their piezotronic response. The work improves the grain boundary barrier height theory of piezoelectric ceramics and is expected to have general impact on piezotronicsand other junction devices.

Item Type: Article
Erschienen: 2018
Creators: Xu, Bai-Xiang and Zhou, Ziqi and Keil, Peter and Frömling, Till
Title: An extended grain boundary barrier height model including the impact of internal electric field
Language: English
Abstract:

An extended phenomenological model is proposed to rationalize the potential barriers of the varistor like boundaries of piezoelectric semiconductors. This model takes selfconsistently into account the inverse piezoelectric effect of the internal electric field associated with the barrier height at grain boundaries. A double Schottky barrier at a grain boundary gives rise to a strong internal electric field in the depletion layer. Due to the inverse piezoelectric effect, this internal electric field leads to mechanical strain and consequently piezoelectric charge at a grain boundary and also an additional space charge associated with the polarization inhomogeneity. The piezoelectric charges in return impacts the barrier height. Results show that the piezoelectric charge induced by the internal field tends to adjust the grain boundary charge and lowers the barrier height. Furthermore, the barrier height becomes less sensitive to mechanical stress and applied voltage if the influence of the internal field is taken into account. The extended model with the inverse piezoelectric effect of the internal field allows to further elucidate their piezotronic response. The work improves the grain boundary barrier height theory of piezoelectric ceramics and is expected to have general impact on piezotronicsand other junction devices.

Journal or Publication Title: AIP Advances
Volume: 8
Number: 115126
Publisher: AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Divisions: 11 Department of Materials and Earth Sciences
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences > Material Science > Mechanics of functional Materials
11 Department of Materials and Earth Sciences > Material Science > Nonmetallic-Inorganic Materials
Date Deposited: 22 Nov 2018 10:46
DOI: 10.1063/1.5049473
Funders: The funding of German Science Foundation to the project Xu121/6-1 and RO954/28-1 within the PAK928 is acknowledged
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