Volume 19, Issue 7 2400311
Research Article

Ab Initio Investigation of Amorphous and Crystalline Arsenic Sesqui-Chalcogenides: Optical Properties Explained by Metavalent Bonding

Ruixuan Chu

Ruixuan Chu

Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049 China

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Xueyang Shen

Xueyang Shen

Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049 China

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Jiayue Wang

Jiayue Wang

Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049 China

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Suyang Sun

Suyang Sun

Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049 China

Institute of Materials, Henan Academy of Sciences, Zhengzhou, 450046 China

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Matthias Wuttig

Matthias Wuttig

Institute of Physics IA, JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany

Peter Grünberg Institute (PGI 10), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

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Riccardo Mazzarello

Corresponding Author

Riccardo Mazzarello

Department of Physics, Sapienza University of Rome, 00185 Rome, Italy

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Wei Zhang

Corresponding Author

Wei Zhang

Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049 China

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First published: 26 November 2024

Abstract

Phase-change materials (PCMs) are employed in both electrical and optical devices exploiting the property contrast between their amorphous and crystalline states. Binary antimony sesqui-chalcogenides such as Sb2Se3 and Sb2S3 are recently shown to be suitable PCMs for low-loss optical applications. In this work, ab initio simulations of arsenic sesqui-chalcogenides are carried out, including As2S3, As2Se3, and As2Te3 to unravel the bonding and optical properties of their crystalline and amorphous phases. Due to the metavalent character of its chemical bonds, crystalline As2Te3 shows a high optical response. However, in crystalline As2S3 and As2Se3, the alignment of p orbitals is fully broken, which results in a very low-extinction coefficient that is already comparable to their amorphous phase. Although As2S3 and As2Se3 display good low-loss optical properties, the overall optical contrast upon phase transition is not sufficient for practical applications. Therefore, it is concluded that arsenic is a useful alloying element in reducing the optical loss of conventional PCMs, but its concentration should be kept at a relatively low level to balance the optical loss and contrast window.

Conflict of Interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are openly available in [CAID Repository] at [https://caid.xjtu.edu.cn/info/1003/1861.htm], reference number [1861].

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