Electric-field-induced annihilation of localized gap defect states in amorphous phase-change memory materials

Konstantinos Konstantinou, Felix C. Mocanu, Jaakko Akola, Stephen R. Elliott

Tutkimustuotos: ArtikkeliScientificvertaisarvioitu

16 Sitaatiot (Scopus)
31 Lataukset (Pure)


Structural relaxation of amorphous phase-change-memory materials has been attributed to defect-state annihilation from the band gap, leading to a time-dependent drift in the electrical resistance, which hinders the development of multi-level memory devices with increased data-storage density. In this computational study, homogeneous electric fields have been applied, by utilizing a Berry-phase approach with hybrid-density-functional-theory simulations, to ascertain their effect on the atomic and electronic structures associated with the mid-gap states in models of the prototypical glassy phase-change material, Ge2Sb2Te5. Above a threshold value, electric fields remove spatially localized defects from the band gap and transform them into delocalized conduction-band-edge electronic states. A lowering of the nearest-neighbor coordination of Ge atoms in the local environment of the defect-host motif is observed, accompanied by a breaking of 4-fold rings. This engineered structural relaxation, through electric-field tuning of electronic and geometric properties in the amorphous phase, paves the way to the design of optimized glasses.

JulkaisuActa Materialia
Varhainen verkossa julkaisun päivämäärä6 marrask. 2021
DOI - pysyväislinkit
TilaJulkaistu - 15 tammik. 2022
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä


  • Jufo-taso 3

!!ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys


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