Heterostructures containing dichalcogenides-new materials with predictable nanoarchitectures and novel emergent properties

Abstract

Heterostructures unconstrained by epitaxy have generated considerable excitement due to the discovery of emergent properties-properties not found in either constituent. Heterostructures enable the surfaces on either side of two-dimensional (2D) layers to be used to systematically investigate phenomena such as superconductivity and magnetism in the 2D limit. The ability to choose constituents facilitates the prediction of emergent properties created by the unusual coordination environments at incommensurate interfaces. There have already been many reviews on heterostructures, focusing on a variety of topics that reflect the diverse interest in this area as well as the potential for new technologies. Hence this review focuses mainly on the synthesis and structural characterization of heterostructures containing transition metal dichalcogenides (TMD). This review only briefly discusses 2D materials and TMD/TMD heterostructure devices and the performances that have been achieved. This review provides a historical context for the rapid development of this field and discusses proposed mechanisms for emergent properties. Up to now, the materials used in heterostructures have mainly been materials with 2D structures, as these compounds can be easily cleaved into ultrathin layers. This review discusses the expansion of heterostructure constituents to include materials that do not have 2D structures. Structural changes and charge redistribution between adjacent (or even more distant) layers are likely to be larger for 3D constituents than with 2D constituents based on known misfit layer compounds. Systematic changes in properties with layer thickness, layer sequences, and the identity of constituents will increase our understanding of emergent properties and how they can be optimized.

Progress in Contact, Doping and Mobility Engineering of MoS2: An Atomically Thin 2D Semiconductor

“…MoS 2 can also be combined with conventional 3D semiconductors (such as Si and III-Vs), other 2D materials (e.g., TMDCs or graphene), and 1D and 0D materials to form various 2D/3D, 2D/2D, 2D/1D and 2D/0D vdW heterostructure devices, respectively, enabling a wide gamut of functionalities [52][53][54][55][56][57][58][59]. Indeed, several device applications such as ultra-scaled FETs [60][61][62][63], digital logic [64][65][66][67], memory [68][69][70][71], analog/RF [72][73][74][75], conventional diodes [76][77][78][79], photodetectors [80][81][82][83], light emitting diodes (LEDs) [84][85][86][87], lasers [88,89], photovoltaics [90][91][92][93], sensors [94][95][96][97], ultra-low-power tunneling-devices such as tunnel-FETs (TFETs)…”

Crystalline tungsten sulfide thin films by atomic layer deposition and mild annealing

“…2,3,10,11 The properties of TMDCs can be further tailored by controlling their thickness, 12,13 surface functionalization, 14 strain, 15,16 doping and alloying, 17,18 and creating heterostructures with other 2D materials. 8,17,19 Tungsten disulfide (WS2) is a semiconducting TMDC, which has an indirect band gap of 1.3-1.4 eV in bulk in the common 2H and 3R phases, which have trigonal prismatic coordination around tungsten and only differ in the stacking of the WS2 layers. 3,20 The band gap of WS2 increases with decreasing thickness and, intriguingly, becomes direct at monolayer thickness with a magnitude of approximately 2.0 eV for the optical band gap.…”

Controlling the Self-Assembly of New Metastable Tin Vanadium Selenides Using Composition and Nanoarchitecture of Precursors

“…30,31 In the field of 2D materials, there is significant interest in the synthesis of heterostructures, especially those containing layered dichalcogenides because of their diverse properties and exfoliable nature due to weak van der Waals interactions between strongly bonded Se−M−Se layers. 32 The system explored here, [(SnSe 2 ) 1+δ ] 1 (VSe 2 ) 1 , is interesting because the phase diagram of Sn−V−Se contains only one ternary equilibrium phase, SnVSe 3 , the misfit layer compound (SnSe) 1 (VSe 2 ) 1 . 3 3 The metastable heterostructure [(SnSe 2 ) 1+δ ] 1 (VSe 2 ) 1 lies on the tie line connecting SnSe 2 and VSe 2 .…”