Synergy effect of co-doping Sc and Y in Sb2Te3 for phase-change memory. Issue 20 (4th May 2020)

• Record Type: Journal Article
• Authors: Hu, Shuwei; Xiao, Jiankai; Zhou, Jian; Elliott, Stephen R.; Sun, Zhimei
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 20(2020)
• Page Start: 6672
• Page End: 6679
• Publication Date: 2020-05-04
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc01693d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Co-doping Sc and Y is a feasible way to obtained better-performance and moderate-cost Sb2 Te3 phase-change materials. Abstract : Sb2 Te3 phase-change material possesses the highest crystallization speed and hence the highest operating speed among investigated phase-change systems. Doping with Y or Sc has been exploited to optimize the performance of Sb2 Te3, yet the substituted Y atoms are strongly clustered, while Sc is extremely expensive and thus is unfavourable for commercialization. In this work, we have successfully obtained better-performance and moderate-cost phase-change materials by co-doping Sc and Y based on ab initio calculations and ab initio molecular-dynamics simulations (AIMD). Sc can shrink the lattice while Y expands the lattice, which makes a perfect match between original and co-doped configurations and hence can benefit by maximizing the release of lattice strain. The co-doping increases the band gap to around 0.5 eV, and the concentration ratio of Sc and Y dopants provides an advantageous tool for controlling the electronic structure. Results of calculations using the BoltzTraP code show that co-doping can result in a significant reduction in the electrical conductivity at room temperature. AIMD simulation of amorphous co-doped Sb2 Te3 shows that the incorporation of Sc and Y atoms can effectively improve the thermal stability of amorphous Sb2 Te3 . Overall, co-doping Sc and Y is a feasible way to improve the properties of Sb2 Te3 for phase-change memory applications.