First-principles study of structural, elastic, electronic and thermodynamic properties of topological insulator Sb2Te3 under pressure

Zhang, Huaiyong; Chen, Yan; Tang, Mei; Chen, Xiangrong; Ji, Guang-Fu

doi:10.1016/j.commatsci.2014.09.045

Cited by 17 publications

(11 citation statements)

References 38 publications

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“…In contrast with a-ST, large electron localization and strong electronic cloud density can be clearly visualized at Sb atoms in a-STSe, which is denoted lone-pair electrons or nonbonding electrons. , The main reason contributing to the improved stability of a-STSe, compared to that of pristine ST, is the stronger reciprocity between Sb and Se than that between Sb and Te. Figure c shows a typical local defective structure pattern for charge localization of c-ST with the electrons accumulated between Sb atoms and Te atoms, which indicates that Sb and Te atoms are covalently bonded . Compared with pristine c-ST, c-STSe possesses a larger electron clustered at the Sb–Se bonds (Figure d), indicating the enhanced localization and stronger Sb–Se bonds than Sb–Te bonds, which is reasonable for the stability of Sb–Se bonds and consistent with XPS results.…”

Section: Resultssupporting

confidence: 81%

“…Figure 3c shows a typical local defective structure pattern for charge localization of c-ST with the electrons accumulated between Sb atoms and Te atoms, which indicates that Sb and Te atoms are covalently bonded. 45 Compared with pristine c-ST, c-STSe possesses a larger electron clustered at the Sb−Se bonds (Figure 3d), indicating the enhanced localization and stronger Sb−Se bonds than Sb−Te bonds, which is reasonable for the stability of Sb−Se bonds and consistent with XPS results. On the other hand, the unsatisfied thermal stability of amorphous ST constrained the application in phase change memory; consequently, the effect of Se on the thermal stability of a-ST is a major concern for the industry.…”

Section: Methodssupporting

confidence: 81%

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Ultra-Stable, Endurable, and Flexible Sb₂Te_xSe_3–x Phase Change Devices for Memory Application and Wearable Electronics

Chen

et al. 2022

ACS Appl. Mater. Interfaces

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Flexible memory and wearable electronics represent an emerging technology, thanks to their reliability, compatibility, and superior performance. Here, an Sb2Te x Se3–x (STSe) phase change material was grown on flexible mica, which not only exhibited superior nature in thermal stability for phase change memory application but also revealed novel function performance in wearable electronics, thanks to its excellent mechanical reliability and endurance. The thermal stability of Sb2Te3 was improved obviously with the crystallization temperature elevated 60 K after Se doping, for the enhanced charge localization and stronger bonding energy, which was validated by the Vienna ab initio simulation package calculations. Based on the ultra-stability of STSe, the STSe-based phase change memory shows 65 000 reversible phase change ability. Moreover, the assembled flexible device can show real-time monitoring and recoverability response in sensing human activities in different parts of the body, which proves its effective reusability and potential as wearable electronics. Most importantly, the STSe device presents remarkable working reliability, reflected by excellent endurance over 100 s and long retention over 100 h. These results paved a novel way to utilize STSe phase change materials for flexible memory and wearable electronics with extreme thermal and mechanical stability and brilliant performance.

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Section: Resultssupporting

confidence: 81%

Section: Methodssupporting

confidence: 81%

Ultra-Stable, Endurable, and Flexible Sb₂Te_xSe_3–x Phase Change Devices for Memory Application and Wearable Electronics

Chen

et al. 2022

ACS Appl. Mater. Interfaces

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“…The Sb 2 Te 3 radial scan (brown curve) is characterized by a series of Bragg reflections along the symmetric rod (00.3 l ), reflecting its highly periodic layered structure. The separation between the peaks allows inferring the c lattice constant (30.44 ± 0.11 Å), which is very close to previous reports . In analogy to the Bi 2+ x Te 3 system, the excess of Sb produces remarkable structural changes in the material, as testified by the continuous evolution of the diffraction curves.…”

Section: Growth and X‐ray Diffractionsupporting

confidence: 87%

Interplay between Structural and Thermoelectric Properties in Epitaxial Sb₂₊_xTe₃ Alloys

Cecchi

Dragoni

Kriegner

et al. 2018

Adv Funct Materials

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In recent years strain engineering is proposed in chalcogenide superlattices (SLs) to shape in particular the switching functionality for phase change memory applications. This is possible in Sb 2 Te 3 /GeTe heterostructures leveraging on the peculiar behavior of Sb 2 Te 3 , in between covalently bonded and weakly bonded materials. In the present study, the structural and thermoelectric (TE) properties of epitaxial Sb 2+x Te 3 films are shown, as they represent an intriguing option to expand the horizon of strain engineering in such SLs. Samples with composition between Sb 2 Te 3 and Sb 4 Te 3 are prepared by molecular beam epitaxy. A combination of X-ray diffraction and Raman spectroscopy, together with dedicated simulations, allows unveiling the structural characteristics of the alloys. A consistent evaluation of the structural disorder characterizing the material is drawn as well as the presence of both Sb 2 and Sb 4 slabs is detected. A strong link exists among structural and TE properties, the latter having implications also in phase change SLs. A further improvement of the TE performances may be achieved by accurately engineering the intrinsic disorder. The possibility to tune the strain in designed Sb 2+x Te 3 /GeTe SLs by controlling at the nanoscale the 2D character of the Sb 2+x Te 3 alloys is envisioned.

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“…For crystalline Sb2Se3, Cao et al[82] obtained Eg of 0.19 eV by including vdW interactions, much less than our value of 0.55 eV. For crystalline Sb2Te3, the Eg obtained by using GGA and GGA + vdW are 0.036 eV and 0.136 eV respectively[70,83] while another study[71] gave Eg As2Te3 reported its Eg to be 0.300 eV from calculation and 0.430 eV from experiment. Our calculated value of 0.627 eV for As2Te3 is almost twice as large.A recent by experimental study using optical transmission spectra has been conducted byPan et al to investigate Eg of amorphous GeSe2[68].…”

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confidence: 65%

Total Bond Order Density as a Quantum Mechanical Metric for Materials Design: Application to Chalcogenide Crystals

Hasan¹,

Baral²,

Ching³

2019

Preprint

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Materials design for processing and application requires fundamental understanding of their properties based interatomic interaction. The use of the novel concept of total bond order density (TBOD) as a single quantum mechanical metric to characterize the internal cohesion of a crystal and correlate with the calculated physical properties is particularly appealing. This requires detailed first-principles calculation of the electronic structure, interatomic bonding and related properties. In this article, we use this new concept and apply it to chalcogenide crystals based on data obtained from 25 crystals: Ag2S, Ag2Se, Ag2Te, As2S3, As2Se3, As2Te3, As4Se4, Cu2S, Cu2Se, Cu2Te, Cu4GeS4, Cu2SnS3, Cu2SnSe3, GeS2, GeSe2, Ge4Se9, Sb2S3, Sb2Se3, Sb2Te3, SnS, SnSe, CdSe, CdTe, ZnSe, and ZnTe. Together with the calculated optical and mechanical properties, we demonstrate the efficacy of using this novel approach for materials design that could facilitate the exploration and development of new chalcogenide crystals and glasses. Moreover, the TBOD and its partial components (PBOD) could be the key descriptors in machine learning protocol for broader scale design when a large database is available.

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First-principles study of structural, elastic, electronic and thermodynamic properties of topological insulator Sb2Te3 under pressure

Cited by 17 publications

References 38 publications

Ultra-Stable, Endurable, and Flexible Sb₂Te_xSe_3–x Phase Change Devices for Memory Application and Wearable Electronics

Ultra-Stable, Endurable, and Flexible Sb₂Te_xSe_3–x Phase Change Devices for Memory Application and Wearable Electronics

Interplay between Structural and Thermoelectric Properties in Epitaxial Sb₂₊_xTe₃ Alloys

Total Bond Order Density as a Quantum Mechanical Metric for Materials Design: Application to Chalcogenide Crystals

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First-principles study of structural, elastic, electronic and thermodynamic properties of topological insulator Sb2Te3 under pressure

Cited by 17 publications

References 38 publications

Ultra-Stable, Endurable, and Flexible Sb2TexSe3–x Phase Change Devices for Memory Application and Wearable Electronics

Ultra-Stable, Endurable, and Flexible Sb2TexSe3–x Phase Change Devices for Memory Application and Wearable Electronics

Interplay between Structural and Thermoelectric Properties in Epitaxial Sb2+xTe3 Alloys

Total Bond Order Density as a Quantum Mechanical Metric for Materials Design: Application to Chalcogenide Crystals

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Product

Resources

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Ultra-Stable, Endurable, and Flexible Sb₂Te_xSe_3–x Phase Change Devices for Memory Application and Wearable Electronics

Ultra-Stable, Endurable, and Flexible Sb₂Te_xSe_3–x Phase Change Devices for Memory Application and Wearable Electronics

Interplay between Structural and Thermoelectric Properties in Epitaxial Sb₂₊_xTe₃ Alloys