Graphene–MoS2 hybrid structures for multifunctional photoresponsive memory devices

Abstract

Combining the electronic properties of graphene and molybdenum disulphide (MoS2) in hybrid heterostructures offers the possibility to create devices with various functionalities. Electronic logic and memory devices have already been constructed from graphene-MoS2 hybrids, but they do not make use of the photosensitivity of MoS2, which arises from its optical-range bandgap. Here, we demonstrate that graphene-on-MoS2 binary heterostructures display remarkable dual optoelectronic functionality, including highly sensitive photodetection and gate-tunable persistent photoconductivity. The responsivity of the hybrids was found to be nearly 1 × 10(10) A W(-1) at 130 K and 5 × 10(8) A W(-1) at room temperature, making them the most sensitive graphene-based photodetectors. When subjected to time-dependent photoillumination, the hybrids could also function as a rewritable optoelectronic switch or memory, where the persistent state shows almost no relaxation or decay within experimental timescales, indicating near-perfect charge retention. These effects can be quantitatively explained by gate-tunable charge exchange between the graphene and MoS2 layers, and may lead to new graphene-based optoelectronic devices that are naturally scalable for large-area applications at room temperature.

Photogating in Low Dimensional Photodetectors

“…To achieve a high performance, graphene is preferred to be used as the channel of a hybrid structure due to its high mobility 32, 39, 88, 89, 90, 91. In the year of 2013, Roy et al incorporated graphene with MoS 2 wherein graphene acts as the channel and MoS 2 acts as the gating layer, as shown in Figure 9 a 32. Negative back‐gate voltage induced band alignment at the interface enables photoexcited electrons transfer to graphene whereas holes remain in MoS 2 .…”

“…Responsivity and response time of part current state‐of‐the‐art low dimensional photodetectors 17, 31, 32, 39, 40, 44, 47, 67, 99, 100, 101, 102, 103, 104. The blue line represents a typical magnitude order of GBP for traditional high‐performance thin‐film photodetectors.…”

Emerging Trends in Phosphorene Fabrication towards Next Generation Devices

“…The monolayer of BP, known as phosphorene, exhibits physical properties that can be significantly different from those of its bulk counterpart 16. Phosphorene has changed the landscape of many research areas in science and technology, particularly in condensed matter physics, and it has received much attention recently for its use as the base component of novel nanodevices, e.g., transistors, nanomechanical resonators, photovoltaics, photodetectors, batteries and sensors 9, 10, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37…”

Independent Band Modulation in 2D van der Waals Heterostructures via a Novel Device Architecture

“…Recently, considerable research interest has been intrigued by the vertically stacked vdWs integration of various 2DLMs, which provides infinite possibilities by overcoming the limitation of lattice matching and processing compatibility 6, 7, 8, 9, 10, 11, 12, 13, 14. Among various categories of vertically stacked vdWs heterostructured devices, the tunneling field effect transistor (TFET), which provides a promising sub‐60‐mV dec −1 subthreshold swing (SS), has been regarded as a promising application of vdWs heterostructure for future energy‐efficient electronics 15, 16, 17, 18, 19…”