Ultrahigh drive current and large selectivity in GeS selector

Shujing Jia (1, 2) , Huanglong Li (3, 4) , Tamihiro Gotoh (5) , Christophe Longeaud (6) , Bin Zhang (7) , Juan Lyu (3) , Shilong Lv (1) , Min Zhu (1) , Zhitang Song (1) , Qi Liu (2) , John Robertson (8) , Ming Liu (2)

1 State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences
2 IMETU - Institute of Microelectronics [Beijing]
3 THU - Tsinghua University [Beijing]
4 Chinese Institute for Brain Research
5 Graduate School of Science and Technology,, Gunma University
6 GeePs - Laboratoire Génie électrique et électronique de Paris
7 Chongqing University [Chongqing]
8 Engineering Department

Selector devices are indispensable components of large-scale nonvolatile memory and neuromorphic array systems. Besides the conventional silicon transistor, two-terminal ovonic threshold switching device with much higher scalability is currently the most industrially favored selector technology. However, current ovonic threshold switching devices rely heavily on intricate control of material stoichiometry and generally suffer from toxic and complex dopants. Here, we report on a selector with a large drive current density of 34 MA cm −2 and a~10 6 high nonlinearity, realized in an environment-friendly and earth-abundant sulfide binary semiconductor, GeS. Both experiments and first-principles calculations reveal Ge pyramid-dominated network and high density of near-valence band trap states in amorphous GeS. The high-drive current capacity is associated with the strong Ge-S covalency and the high nonlinearity could arise from the synergy of the mid-gap traps assisted electronic transition and local Ge-Ge chain growth as well as locally enhanced bond alignment under high electric field.

Domains: Physics [physics]

Shujing Jia, Huanglong Li, Tamihiro Gotoh, Christophe Longeaud, Bin Zhang, et al.. Ultrahigh drive current and large selectivity in GeS selector. Nature Communications, 2020, 11 (1), pp.4636 (2020). ⟨10.1038/s41467-020-18382-z⟩. ⟨hal-03024841⟩