Designing Phase-Change Superlattices via Selectively Modulating Stochasticity and Covalency to Efficiently Implement Stable Multi-Level Memory

ACS Applied Energy Materials

Abstract

Interfacial phase-change materials (iPCMs), composed of superlattice architecture with GeTe and Sb 2 Te 3, show outstanding advancements in phase-change characteristics over alloy-based PCMs. Owing to their strongly aligned anisotropic structures, iPCMs reduce unnecessary entropic loss during phase-change operation. By conducting meticulous structural analysis, this study elucidates the structural and atomic behaviors of the phase-change process within different memory states in iPCM. Moreover, the overall phase-change properties of iPCMs are enhanced with doping Ti by selectively modulating the covalency of interatomic bonds. In addition to the improvements of the conventional phase-change characteristics, suppressed resistance drift and confined multi-level states present the potential of Ti-doped iPCM as a neuromorphic memristor. The bonding characteristics of iPCMs can be precisely tuned by selectively incorporating transition metals into either the even or odd layers of the superlattice, thereby engineering anisotropic covalency at the atomic scale. This study lays the foundation for designing frameworks for phase-change superlattices, which facilitate the development of next-generation neuromorphic memories.

Authors 13

1. Hyeonwook Lim

   Yonsei University

   Affiliation as printed

   Department of Physics, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea

2. Chang Woo Lee

   Yonsei University

   Affiliation as printed

   Department of Physics, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea

3. Kyu-Jin Jo

   Sungkyunkwan University

   Affiliation as printed

   School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seoburo, Suwon 16419, Republic of Korea

4. Dasol Kim Aachen

   RWTH Aachen University

   Affiliation as printed

   Institute of Physics, Physics of Novel Materials

   RWTH Aachen University

5. Ju Hwan Park

   Seoul National University of Science and Technology

   Affiliation as printed

   Department of Materials Science and Engineering

   Seoul National University of Science and Technology

6. Kwangsik Jeong

   Yonsei University

   Affiliation as printed

   Department of AI semiconductor

   Yonsei University

7. Hoedon Kwon

   Yonsei University

   Affiliation as printed

   Department of Physics, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea

8. Yeonwoo Seong

   Yonsei University

   Affiliation as printed

   Department of Physics, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea

9. Ho-Jun Lee

   Yonsei University

   Affiliation as printed

   Department of Physics, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea

10. Gihyeon Kwon

    Yonsei University

    Affiliation as printed

    Department of Physics, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea

11. Byung Joon Choi

    Seoul National University of Science and Technology

    Affiliation as printed

    Department of Materials Science and Engineering

    Seoul National University of Science and Technology

12. Cheol‐Woong Yang

    Sungkyunkwan University

    Affiliation as printed

    School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seoburo, Suwon 16419, Republic of Korea

13. Mann–Ho Cho corresponding

    Yonsei University

    Affiliation as printed

    Department of Physics, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea

    Department of system semiconductor Engineering, Yonsei University, 50 Yonsei-ro, Seoul 03722, Republic of Korea