Structure and charge transport of amorphous \(Cu\)-doped \(Ta_2O_5\) : An ab initio study

In this paper, we present ab initio computer models of Cu-doped amorphous Ta2O5 , a promising candidate for Conducting Bridge Random Access Memory (CBRAM) memory devices, and study the structural, electronic, charge transport and vibrational properties based on plane-wave density functional methods....

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Bibliographic Details
Published inarXiv.org
Main Authors Thapa, Rajendra, Bhattarai, Bishal, Kozicki, M N, Subedi, Kashi N, Drabold, D A
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 16.03.2020
Subjects
Animation
Charge transport
Conduction
Electric bridges
Electrical resistivity
Electron transport
Mathematical models
Memory devices
Random access memory
Tantalum
Tantalum oxides
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Summary:In this paper, we present ab initio computer models of Cu-doped amorphous Ta2O5 , a promising candidate for Conducting Bridge Random Access Memory (CBRAM) memory devices, and study the structural, electronic, charge transport and vibrational properties based on plane-wave density functional methods. We offer an atomistic picture of the process of phase segregation/separation between Cu and Ta2O5 subnetworks. Electronic calculations show that the models are conducting with extended Kohn-Sham orbitals around the Fermi level. In addition to that, we also characterize the electronic transport using the Kubo-Greenwood formula modified suitably to calculate the space-projected conductivity (SPC). Our SPC calculations show that Cu clusters and under-coordinated Ta adjoining the Cu are the conduction-active parts of the network. We also report information about the dependence of the electrical conductivity on the connectivity of the Cu sub-matrix. Vibrational calculations for one of the models has been undertaken with an emphasis on localization and animation of representative modes.
ISSN:2331-8422
DOI:10.48550/arxiv.2003.07346