High-Performance Photoinduced Memory with Ultrafast Charge Transfer Based on MoS2 /SWCNTs Network Van Der Waals Heterostructure

Small. 2019 Jan;15(3):e1804661. doi: 10.1002/smll.201804661. Epub 2018 Dec 13.

Abstract

Photoinduced memory devices with fast program/erase operations are crucial for modern communication technology, especially for high-throughput data storage and transfer. Although some photoinduced memories based on 2D materials have already demonstrated desirable performance, the program/erase speed is still limited to hundreds of micro-seconds. A high-speed photoinduced memory based on MoS2 /single-walled carbon nanotubes (SWCNTs) network mixed-dimensional van der Waals heterostructure is demonstrated here. An intrinsic ultrafast charge transfer occurs at the heterostructure interface between MoS2 and SWCNTs (below 50 fs), therefore enabling a record program/erase speed of ≈32/0.4 ms, which is faster than that of the previous reports. Furthermore, benefiting from the unique device structure and material properties, while achieving high-speed program/erase operation, the device can simultaneously obtain high program/erase ratio (≈106 ), appropriate storage time (≈103 s), record-breaking detectivity (≈1016 Jones) and multibit storage capacity with a simple program/erase operation. It even has a potential application as a flexible optoelectronic device. Therefore, the designed concept here opens an avenue for high-throughput fast data communications.

Keywords: photoinduced memory; program/erase performance; ultrafast charge transfer; van der Waals heterostructures.