Materials Screening for Disorder‐Controlled Chalcogenide Crystals for Phase‐Change Memory Applications. Issue 9 (25th January 2021)

• Record Type: Journal Article
• Authors: Xu, Yazhi; Wang, Xudong; Zhang, Wei; Schäfer, Lisa; Reindl, Johannes; vom Bruch, Felix; Zhou, Yuxing; Evang, Valentin; Wang, Jiang‐Jing; Deringer, Volker L.; Ma, En; Wuttig, Matthias; Mazzarello, Riccardo
• Is Part Of: Advanced materials. Volume 33:Issue 9(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-01-25
• Subjects: Anderson insulators -- metal–insulator transitions -- neuromorphic computing -- phase‐change materials; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202006221
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: 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 Sb2 Te3, 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. Abstract : Ab initio simulations and transport experiments elucidate why Sb2 Te3 can form an insulating rocksalt structure, extending the exploration of Anderson insulators to binary chalcogenides. A systematic computational screening over binary and ternary chalcogenides, which leads to an in‐depth understanding of the critical factors that affect the stability of the rocksalt structure is also carried out.