Time-dependent density-functional theory molecular-dynamics study on amorphization of Sc-Sb-Te alloy under optical excitation

npj Computational Materials, vol. 6

Abstract

Abstract Recently, all-optical memory and optical-computation properties of phase-change materials are receiving intensive attention. Because writing/erasing information in these devices is usually achieved by laser pulses, the interaction between the laser and the phase-change materials becomes a key issue for such new applications. In this work, by a time-dependent density-functional theory molecular-dynamics study, the physics underlying the optical excitation induced amorphization of Sc-Sb-Te is revealed, which goes back to superatom-like Sc-centered structural motifs. These motifs are found to be still robust under the excitation. A selected occupation of the Sc d-t2g orbitals (as a result of optical excitation) leads to a significant change of Sc-centered bond angles. In addition, the especially weak Sb-Te bonds next to the Sc motifs are further diminished by excitations. Therefore, the Sc-centered motifs can promote breaking, switching, and reforming of the surrounding Sb-Te network and, therefore, facilitate the amorphization of Sc-Sb-Te. The study shows the unique role of Sc-centered motifs in optically induced phase transition, and displays potential applications of Sc-Sb-Te alloys in optical memory/computation.

Authors 9

1. Xuepeng Wang

   Jilin University · State Key Laboratory on Integrated Optoelectronics

   Affiliation as printed

   State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 130012, Changchun, China

2. Xianbin Li corresponding

   Jilin University · State Key Laboratory on Integrated Optoelectronics

   Affiliation as printed

   State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 130012, Changchun, China

3. Nian‐Ke Chen

   Jilin University · State Key Laboratory on Integrated Optoelectronics

   Affiliation as printed

   State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 130012, Changchun, China

4. Junhyeok Bang

   Chungbuk National University

   Affiliation as printed

   Department of Physics, Chungbuk National University, 28644, Chungbuk, Republic of Korea

5. Ryky Nelson Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry, RWTH Aachen University, 52056, Aachen, Germany

6. Christina Ertural Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry, RWTH Aachen University, 52056, Aachen, Germany

7. Richard Dronskowski Aachen Institute of Inorganic Chemistry

   Shenzhen Polytechnic University · RWTH Aachen University

   Affiliation as printed

   Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 518055, Shenzhen, China

   Institute of Inorganic Chemistry, RWTH Aachen University, 52056, Aachen, Germany

8. Hong‐Bo Sun corresponding

   Jilin University · State Key Laboratory on Integrated Optoelectronics · Tsinghua University

   Affiliation as printed

   State Key Lab of Precision Measurement Technology and Instruments Department of Precision Instrument, Tsinghua Univerwsity, 100084, Beijing, China

   State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 130012, Changchun, China

9. Shengbai Zhang corresponding

   Rensselaer Polytechnic Institute

   Affiliation as printed

   Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA