Van der Waals (vdW) heterostructures have drawn much interest over the last decade owing to their absence of dangling bonds and their intriguing low-dimensional properties. The emergence of 2D materials has enabled the achievement of significant progress in both the discovery of physical phenomena and the realization of superior devices. In this work, the group IV metal chalcogenide 2D-layered Ge4Se9 is introduced as a new selection of insulating vdW material. 2D-layered Ge4Se9 is synthesized with a rectangular shape using the metalcorganic chemical vapor deposition system using a liquid germanium precursor at 240 °C. By stacking the Ge4Se9 and MoS2, vdW heterostructure devices are fabricated with a giant memory window of 129 V by sweeping back gate range of ±80 V. The gate-independent decay time reveals that the large hysteresis is induced by the interfacial charge transfer, which originates from the low band offset. Moreover, repeatable conductance changes are observed over the 2250 pulses with low non-linearity values of 0.26 and 0.95 for potentiation and depression curves, respectively. The energy consumption of the MoS2/Ge4Se9 device is about 15 fJ for operating energy and the learning accuracy of image classification reaches 88.3%, which further proves the great potential of artificial synapses.
|Publication status||Published - 2022 Oct 13|
Bibliographical noteFunding Information:
G.N., H.S., and H.C. contributed equally to this work. K.K. was supported by the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (grant no. 2020M3D1A1110659, 2020M3F3A2A01082618, 2021R1C1C1007292, 2022M3H4A1A01010325) and Korea Institute of Science and Technology Institutional Program (grant no. 2V07080‐P148). J.Y.K. was supported by the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (grant no. 2021M3F3A2A01037738), Institute of Information and Communications Technology Planning and Evaluation (IITP) (grant no. 2021001776) and Korea Institute of Science and Technology (KIST) through 2E31550. G.‐H.L. was supported by Research Institute of Advanced Materials (RIAM), Institute of Engineering Research and Institute of Applied Physics in Seoul National University and the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (grant no. 2021M3F3A2A01037858).
© 2022 Wiley-VCH GmbH.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering