Lateral Growth of MoS 2 2D Material Semiconductors Over an Insulator Via Electrodeposition (original) (raw)

Lateral Growth of MoS ₂ 2D Material Semiconductors Over an Insulator Via Electrodeposition

Advanced electronic materials, 2021

Some of these demonstrations were implemented for wearable applications by exploiting the material's exceptional robustness and flexibility. [5,6] However, there remain major obstacles that hinder the industrial adoption of MoS 2 and other 2D TMDC materials. The most challenging obstacle has been finding an industrially compatible method that enables the production of these materials on a mass scale. We have recently demonstrated that electrodeposition is a potentially viable method for solving this challenge. [7,8] Electrodeposition offers important advantages in 2D material production over other methods such as chemical vapor deposition (CVD), [9,10] sputtering, [11] or atomic layer deposition (ALD). [12] Electrodeposition is not a lineof-sight deposition method as material growth occurs at electrical contacts and is controlled by electrical potential or current. [13] It can hence be utilized to deposit materials over 3D surfaces including patterned nanostructures of high aspect ratios. [14-17] In addition, electrodeposition is usually performed at room temperature, avoiding harsh environments such as plasma or extremely high temperatures, which can damage pre-existing materials on the substrate, such as graphene electrodes. [7] However, there is an important limitation with electrodeposition that needs to be overcome. This method requires an electrically conductive surface from which materials are traditionally grown vertically. [18] Depositing a semiconductor material on a conductor provides a low resistance current path in planar (opto-) electronic devices such as transistors and photodetectors, thus limiting the use of electrodeposition traditionally to certain vertical device structures or metal interconnects (through the dual damascene process). [19] Prior to the work described herein, this limitation has been a drawback, specifically for developing 2D material based devices where planar structures that exploit the unique 2D properties of the material are the "natural" route forward. [20-23] Creating innovative techniques to electrodeposit planar 2D materials over non-conducting surfaces would solve this limitation and open new routes where the insulator base can be utilized, such as in transistor gating. In the early 1990s, Nishizawa et al. described the electrochemical growth of poly(pyrrole) Developing novel techniques for depositing transition metal dichalcogenides is crucial for the industrial adoption of 2D materials in optoelectronics. In this work, the lateral growth of molybdenum disulfide (MoS 2) over an insulating surface is demonstrated using electrochemical deposition. By fabricating a new type of microelectrodes, MoS 2 2D films grown from TiN electrodes across opposite sides are connected over an insulating substrate, hence, forming a lateral device structure through only one lithography and deposition step. Using a variety of characterization techniques, the growth rate of MoS 2 is shown to be highly anisotropic with lateral to vertical growth ratios exceeding 20-fold. Electronic and photo-response measurements on the device structures demonstrate that the electrodeposited MoS 2 layers behave like semiconductors, confirming their potential for photodetection applications. This lateral growth technique paves the way toward room temperature, scalable, and site-selective production of various transition metal dichalcogenides and their lateral heterostructures for 2D materials-based fabricated devices.

Lateral electrodeposition of MoS2 semiconductor over an insulator

2021

Developing novel techniques for depositing transition metal dichalcogenides is crucial for the industrial adoption of 2D materials in optoelectronics. In this work, the lateral growth of molybdenum disulfide (MoS2) over an insulating surface is demonstrated using electrochemical deposition. By fabricating a new type of microelectrodes, MoS2 2D films grown from TiN electrodes across opposite sides have been connected over an insulating substrate, hence, forming a lateral device structure through only one lithography and deposition step. Using a variety of characterization techniques, the growth rate of MoS2 has been shown to be highly anisotropic with lateral to vertical growth ratios exceeding 20-fold. Electronic and photoresponse measurements on the device structures demonstrate that the electrodeposited MoS2 layers behave like semiconductors, confirming their potential for photodetection applications. This lateral growth technique paves the way towards room temperature, scalable a...