This item is non-discoverable
Charge ordering and dion-jacobson semiconducting ferroelectric materials towards artificial synapses
Loading...
Authors
Guo, Yuwei
Issue Date
2020-12
Type
Electronic thesis
Thesis
Thesis
Language
en_US
Keywords
Materials engineering
Alternative Title
Abstract
Ferroelectric materials have demonstrated their great potential in non-volatile memoriesand high-performance artificial synapses. However, in the development of ultrafast and highdensity
synaptic devices using novel semiconducting charge ordering and Dion-Jacobson
ferroelectrics, basic knowledge of their crystal and domain structures are limited . In this
dissertation, I would like to present two of our experimental efforts in pursing the relevant
fundamental understanding:
First, I present our experimental discovery of the first room temperature ferroelectric
semiconductor Ag2BiO3. Its electronic ferroelectricity is induced by coexistence of bond length
disproportionation and charge disproportionation hosted by a couple of degenerate low-symmetry
phases (Pnn2 and Pc). I demonstrate the existence of a photo-ferroelectric synaptic behavior in
Ag2BiO3-based two-terminal device. I further propose a circuit-implementation of such optical
synapse in conducting neuromorphic-like computing allowing non-destructive and energy
efficient analog read-out. The simulated performance suggests such photo-ferroelectric synapse is
promising for high-performance neuromorphic computing.
Second, I employ a Dion-Jacobson layered oxide CsBiNb2O7, which was predicted to be a
ferroelectric material, as a model system to study the effect of quasi-2D interlayer interaction on
ferroelectric domain structure with atomic scale analysis. I reveal the existence of unit-cell thick
ferroelectric domain size as well as both 180° and 90° domain walls in free-standing CsBiNb2O7.
Our understanding of the quasi-2D ferroelectric material’s domain structure may suggest new
material categories to achieve unit-cell thick domain structures and shed light on promising
materials solutions for next-generation microelectronic and synaptic devices.
Description
December 2020
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY