Multi-terminal memtransistors from polycrystalline monolayer molybdenum disulfide

Vinod K. Sangwan, Hong Sub Lee, Hadallia Bergeron, Itamar Balla, Megan E. Beck, Kan Sheng Chen, Mark C Hersam

Research output: Contribution to journalArticle

148 Citations (Scopus)

Abstract

Memristors are two-terminal passive circuit elements that have been developed for use in non-volatile resistive random-access memory and may also be useful in neuromorphic computing. Memristors have higher endurance and faster read/write times than flash memory and can provide multi-bit data storage. However, although two-terminal memristors have demonstrated capacity for basic neural functions, synapses in the human brain outnumber neurons by more than a thousandfold, which implies that multi-terminal memristors are needed to perform complex functions such as heterosynaptic plasticity. Previous attempts to move beyond two-terminal memristors, such as the three-terminal Widrow-Hoff memristor and field-effect transistors with nanoionic gates or floating gates, did not achieve memristive switching in the transistor. Here we report the experimental realization of a multi-terminal hybrid memristor and transistor (that is, a memtransistor) using polycrystalline monolayer molybdenum disulfide (MoS2) in a scalable fabrication process. The two-dimensional MoS2 memtransistors show gate tunability in individual resistance states by four orders of magnitude, as well as large switching ratios, high cycling endurance and long-term retention of states. In addition to conventional neural learning behaviour of long-term potentiation/depression, six-terminal MoS2 memtransistors have gate-tunable heterosynaptic functionality, which is not achievable using two-terminal memristors. For example, the conductance between a pair of floating electrodes (pre- and post-synaptic neurons) is varied by a factor of about ten by applying voltage pulses to modulatory terminals. In situ scanning probe microscopy, cryogenic charge transport measurements and device modelling reveal that the bias-induced motion of MoS2 defects drives resistive switching by dynamically varying Schottky barrier heights. Overall, the seamless integration of a memristor and transistor into one multi-terminal device could enable complex neuromorphic learning and the study of the physics of defect kinetics in two-dimensional materials.

Original languageEnglish
Pages (from-to)500-504
Number of pages5
JournalNature
Volume554
Issue number7693
DOIs
Publication statusPublished - Feb 21 2018

    Fingerprint

ASJC Scopus subject areas

  • General

Cite this

Sangwan, V. K., Lee, H. S., Bergeron, H., Balla, I., Beck, M. E., Chen, K. S., & Hersam, M. C. (2018). Multi-terminal memtransistors from polycrystalline monolayer molybdenum disulfide. Nature, 554(7693), 500-504. https://doi.org/10.1038/nature25747