In situ observations of the reversible vacancy ordering process in van der Waals-bonded Ge–Sb–Te thin films and GeTe–Sb2Te3 superlattices

Lotnyk, Andriy; Dankwort, Torben; Hilmi, Isom; Kienle, Lorenz; Rauschenbach, B.

doi:10.1039/c9nr02112d

Cited by 48 publications

(40 citation statements)

References 37 publications

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“…This is because the randomly distributed vacancies in c‐GST become highly ordered vdW gaps in the hexagonal phase. [ 95 ] As more electrons are delocalized, the mobility edge ( E μ ) that separates the localized and delocalized electronic states moves upward, making GST metallic when the Fermi level ( E f ) falls below E μ (Figure 3b). [ 96 ] The full understanding of the relationship between the resistance and the degrees of disorder could help the researchers to design artificial synapses totally in crystalline phases, so that the ageing issue of the glass can be avoided.…”

Section: Fundamentals Of Pcmsmentioning

confidence: 99%

Recent Advances on Neuromorphic Devices Based on Chalcogenide Phase‐Change Materials

Mai

Lin

et al. 2020

Adv Funct Materials

173

120

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Traditional von Neumann computing architecture with separated computation and storage units has already impeded the data processing performance and energy efficiency, calling for emerging neuromorphic electronic and optical devices and systems which can mimic the human brain to shift this paradigm. Material-level innovation has become the key component to this revolution of information technology. Chalcogenide phase-change material (PCM) as a well-acknowledged data-storage medium is a promising candidate to tackle this challenge. In this review, the use of PCMs to implement artificial neurons and synapses from both the electronic and optical respects is discussed, and in particular, the structure-property physics and transition dynamics that enable such brain-inspired and in-memory computing applications are emphasized. Recent advances on the atomic-level amorphous and crystalline structures, transition mechanisms, materials optimization and design, neural and synaptic devices, brain-inspired chips, and computing systems, as well as the future opportunities of PCMs, are summarized and discussed.

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Section: Fundamentals Of Pcmsmentioning

confidence: 99%

Recent Advances on Neuromorphic Devices Based on Chalcogenide Phase‐Change Materials

Mai

Lin

et al. 2020

Adv Funct Materials

173

120

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“…37,51 More interestingly, many phase change materials undergo order-disorder transitions within their crystalline phases. [52][53][54][55][56] This is attributed to the presence of a huge amount of structural vacancies in the materials, which are also responsible for the p-type conductivity of phase change alloys. 57 Depending on the composition, the number of structural vacancies in the cation sublattice can be up to 29% (e.g.…”

Section: Introductionmentioning

confidence: 99%

Phase change thin films for non-volatile memory applications

2019

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“…[ 20 ] The microscopic origin of this transition is the ordering of vacancies into 2D vacancy planes. [ 21,25–30 ]…”

Section: Figurementioning

confidence: 99%

Materials Screening for Disorder‐Controlled Chalcogenide Crystals for Phase‐Change Memory Applications

Wang

Zhang

et al. 2021

Advanced Materials

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Tailoring the degree of disorder in chalcogenide phase‐change materials (PCMs) plays an essential role in nonvolatile memory devices and neuro‐inspired computing. Upon rapid crystallization from the amorphous phase, the flagship Ge–Sb–Te PCMs form metastable rocksalt‐like structures with an unconventionally high concentration of vacancies, which results in disordered crystals exhibiting Anderson‐insulating transport behavior. Here, ab initio simulations and transport experiments are combined to extend these concepts to the parent compound of Ge–Sb–Te alloys, viz., binary Sb2Te3, in the metastable rocksalt‐type modification. Then a systematic computational screening over a wide range of homologous, binary and ternary chalcogenides, elucidating the critical factors that affect the stability of the rocksalt structure is carried out. The findings vastly expand the family of disorder‐controlled main‐group chalcogenides toward many more compositions with a tunable bandgap size for demanding phase‐change applications, as well as a varying strength of spin–orbit interaction for the exploration of potential topological Anderson insulators.

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In situ observations of the reversible vacancy ordering process in van der Waals-bonded Ge–Sb–Te thin films and GeTe–Sb₂Te₃ superlattices

Abstract: Reconfiguration of the structural order in layered Ge–Sb–Te structures is associated with the formation of vacancy layers and readjustment of interplanar spacing.

Cited by 48 publications

References 37 publications

Recent Advances on Neuromorphic Devices Based on Chalcogenide Phase‐Change Materials

Recent Advances on Neuromorphic Devices Based on Chalcogenide Phase‐Change Materials

Phase change thin films for non-volatile memory applications

Materials Screening for Disorder‐Controlled Chalcogenide Crystals for Phase‐Change Memory Applications

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