Gate-tunable non-volatile photomemory effect in MoS ₂ transistors

Abstract

Non-volatile memory devices have been limited to flash architectures that are complex devices. Here, we present a unique photomemory effect in MoS 2 transistors. The photomemory is based on a photodoping effect -a controlled way of manipulating the density of free charges in monolayer MoS 2 using a combination of laser exposure and gate voltage application. The photodoping promotes changes on the conductance of MoS 2 leading to photomemory states with high memory on/off ratio. Such memory states are non-volatile with an expectation of retaining up to 50% of the information for tens of years. Furthermore, we show that the photodoping is gate-tunable, enabling control of the recorded memory states. Finally, we propose a model to explain the photodoping, and we provide experimental evidence supporting such a phenomenon.In summary, our work includes the MoS 2 phototransistors in the non-volatile memory devices and expands the possibilities of memory application beyond conventional memory architectures.

Laser‐Assisted Multilevel Non‐Volatile Memory Device Based on 2D van‐der‐Waals Few‐Layer‐ReS2/h‐BN/Graphene Heterostructures

“…[4,5] Recently non-volatile memories (NVM) based on 2D heterostructures and their tuneable and multibit operation under laser light have been reported. [6][7][8][9][10][11][12][13][14][15] Laser-assisted memory operation provides a new degree of freedom for multifunctional optoelectronic devices with the extra functionality of optically communicated multilevel access. [1,[16][17][18] Laser light can travel through free space without losing power and this allows us to operate optoelectronic devices from a long distance away at low power and with little need for maintenance.…”

Facile Polydimethylsiloxane Treatment of Indium Gallium Zinc Oxide Phototransistor for Visible Light‐Based Multilevel Photomemory

“…Various semiconductor materials have been proposed as candidates to satisfy these requirements, such as carbon composite, perovskite, 2D materials, etc. [ 6–8 ] Among these, indium‐gallium zinc‐oxide (IGZO), a representative oxide semiconductor used in the display industry, has excellent characteristics such as high field‐effect mobility (μ FET ≈10 cm 2 V −1 s −1 ), low off‐current (sub‐pA), and large‐scale deposition capability (up to Gen. 10.5) when used as a channel layer of thin‐film transistors. [ 9–13 ] In order to functionalize the properties of IGZO TFTs, IGZO films’ composition has been controlled through the role of metal cation as follows; in general, In, Ga, and Zn act as modulating mobility through conducting path formation, controlling oxygen vacancies serving as carriers, and stabilizing the amorphous structure by suppressing In 2 O 3 crystallization, respectively.…”

Polarization‐Resolved Broadband MoS2/Black Phosphorus/MoS2 Optoelectronic Memory with Ultralong Retention Time and Ultrahigh Switching Ratio

“…Of these, NOMs based on 2D semiconductors and their van der Waals (vdWs) heterostructures have elicited tremendous attention due to their high absorption coefficient, tunable bandgap, structural flexibility, as well as significant photo‐generated charge trapping caused by their large surface‐to‐volume ratio. [ 13–19 ]…”