Gate-tunable non-volatile photomemory effect in MoS$_2$ transistors

TL;DR

This paper demonstrates a gate-tunable, non-volatile photomemory effect in MoS$_2$ transistors based on photodoping, enabling long-term data retention and control of memory states, expanding memory device possibilities.

Contribution

It introduces a novel photomemory mechanism in MoS$_2$ transistors utilizing photodoping, with experimental validation and a proposed model for the phenomenon.

Findings

High memory on/off ratio achieved

Memory states retain up to 50% of information for decades

Photodoping is controllable via gate voltage

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.