Monolayer MoS 2 Transferred on Arbitrary Substrates for Potential Use in Flexible Electronics

Sharma

Crystal Growth & Design

2021

Self Cite

Direct growth of wafer scale high quality 2D layered materials (2DLMs) on SiO2/Si substrate is still a challenge. The chemical vapor deposition (CVD) technique has played a significant role in achieving a large area continuous film of 2DLMs. CVD growth requires the optimization of many growth parameters such as temperature, amount of precursors, pressure, carrier gas flow and distance between the reactants. However, the role of boundary layer of reactants concentration has not been explored yet. The amount of precursors which leads to the formation of reactants concentration boundary layer has a significant role in controlling the thickness of growing material. Here, we report the role of concentration boundary layer to achieve wafer-scale MoS2 in NaCl-assisted CVD growth at low temperature. Control of boundary layer thickness has led to the synthesis monolayer, bilayer, trilayer, and bulk MoS2 film and flakes in our single-zone CVD at atmospheric pressure. Most importantly, we have synthesized 7 × 2.5 cm 2 area continuous, high quality trilayer MoS2 film with good repeatability. We believe that our approach may lead to synthesize other wafer-scale 2DLMs that will pave the way for nano-and optoelectronics.2

Section: Introductionmentioning

confidence: 99%

NaCl-Assisted CVD Growth of Large-Area High-Quality Trilayer MoS₂ and the Role of the Concentration Boundary Layer

Sharma

Crystal Growth & Design

2021

Self Cite

“…The water-soluble layer was completely dissolved during the transfer, reducing the unintended electron doping in WS 2. 26 This is the reason for that the intensity of the X exciton dominates the intensity of the X – trion in the PL spectrum of transferred WS 2 . Raman and PL spectra confirm that 1L WS 2 retains its optical properties after the transfer.…”

Section: Resultsmentioning

confidence: 99%

Large-Area Transfer of 2D TMDCs Assisted by a Water-Soluble Layer for Potential Device Applications

et al. 2022

Self Cite

Layer transfer offers enormous potential for the industrial implementation of two-dimensional (2D) material technology platforms. However, the transfer method used must retain the as-grown uniformity and cleanliness in the transferred films for the fabrication of 2D material-based devices. Additionally, the method used must be capable of large-area transfer to maintain wafer-scale fabrication standards. Here, a facile route to transfer centimeter-scale synthesized 2D transition metal dichalcogenides (TMDCs) (3L MoS 2 , 1L WS 2 ) onto various substrates such as sapphire, SiO 2 /Si, and flexible substrates (mica, polyimide) has been developed using a water-soluble layer (Na 2 S/Na 2 SO 4 ) underneath the as-grown film. The developed transfer process represents a fast, clean, generic, and scalable technique to transfer 2D atomic layers. The key strategy used in this process includes the dissolution of the Na 2 S/Na 2 SO 4 layer due to the penetration of NaOH solution between the growth substrate and hydrophobic 2D TMDC film. As a proof-of-concept device, a broadband photodetector has been fabricated onto the transferred 3L MoS 2 , which shows photoresponse behavior for a wide range of wavelengths ranging from near-infrared (NIR) to UV. The enhancement in photocurrent was found to be 100 times and 10 times the dark current in the UV and visible regions, respectively. The fabricated photodetector shows a higher responsivity of 8.6 mA/W even at a low applied voltage (1.5 V) and low power density (0.6 μW/mm 2 ). The detector enables a high detectivity of 2.9 × 10 11 Jones. This work opens up the pathway toward flexible electronics and optoelectronics.

“…[ 7 ] By transferring the monolayer flakes on the transparent and flexible substrates, 1L‐MoS 2 can expand its utility to the flexible optoelectronic devices such as flexible field‐effect transistors (FETs), piezoelectric nanogenerators, organic light‐emitting diode displays, foldable displays, and memory devices. [ 8 ]…”

Section: Introductionmentioning

confidence: 99%

“…[ 11 ] The transfer process of 1L‐MoS 2 is also exploited in multiple applications. [ 8 ] First, the transfer process is used in transferring the as‐grown films from the insulating substrates (like sapphire) onto the dielectric substrates (like SiO 2 ) for fabricating the complementary metal‐oxide‐semiconductor (CMOS) devices. [ 12 ] In addition, the transfer process is also extended to the transmission electron microscopy (TEM) sample preparation, [ 13 ] and the fabrication of vertical 2D heterostructures.…”

Section: Introductionmentioning

confidence: 99%

“…[7] By transferring the monolayer flakes on the transparent and flexible substrates, 1L-MoS 2 can expand its utility to the flexible optoelectronic devices such as flexible field-effect transistors (FETs), piezoelectric nanogenerators, organic light-emitting diode displays, foldable displays, and memory devices. [8] Large-area 1L-MoS 2 flakes are necessary to develop the monolayer-based flexible devices, In this context, chemical vapor deposition (CVD) is a proven method for the wafer-scale growth of 1L-MoS 2 . [9] Moreover, CVD is the most viable technique because of its effectiveness in scalability, reproducibility, and production of high optical quality materials.…”

mentioning

confidence: 99%

See 1 more Smart Citation

A Novel Methodology of Using Nonsolvent in Achieving Ultraclean Transferred Monolayer MoS₂

Bhuyan

Madapu

Prabakar

et al. 2022

Adv Materials Inter

the research community because of its intriguing optical and electronic properties. [1] The optical property of a monolayer is distinguishably different from its bulk counterparts. [2] The direct bandgap ≈1.82 eV of 1L-MoS 2 makes it a suitable material for electronic and optoelectronic devices. [3,4] Additionally, the excitons in 1L-MoS 2 possess an extraordinarily high binding energy because of strong quantum confinement and the reduced screening effect. [5] The presence of excitons at ambient temperature enriches the exciton physics and finds application in macroscopic quantum phenomena. [6] Furthermore, the spin-valley coupling and breaking of the spatial inversion symmetry extend the 1L-MoS 2 application from spintronics to valleytronics. [7] By transferring the monolayer flakes on the transparent and flexible substrates, 1L-MoS 2 can expand its utility to the flexible optoelectronic devices such as flexible field-effect transistors (FETs), piezoelectric nanogenerators, organic light-emitting diode displays, foldable displays, and memory devices. [8] Large-area 1L-MoS 2 flakes are necessary to develop the monolayer-based flexible devices, In this context, chemical vapor deposition (CVD) is a proven method for the wafer-scale growth of 1L-MoS 2 . [9] Moreover, CVD is the most viable technique because of its effectiveness in scalability, reproducibility, and production of high optical quality materials. [10] However, direct growth of large-area 1L-MoS 2 onto flexible substrates such as polyethylene-terephthalate (PET) and polyethene-naphthalate (PEN) using the CVD is precluded due to its high growth temperatures ≥ 700 °C. Thus, the transfer of large-area 1L-MoS 2 grown by CVD onto flexible substrates is an inescapable step. [11] The transfer process of 1L-MoS 2 is also exploited in multiple applications. [8] First, the transfer process is used in transferring the as-grown films from the insulating substrates (like sapphire) onto the dielectric substrates (like SiO 2 ) for fabricating the complementary metal-oxide-semiconductor (CMOS) devices. [12] In addition, the transfer process is also extended to the transmission electron microscopy (TEM) sample preparation, [13] and the fabrication of vertical 2D heterostructures. [14] Among 2D material transfer methods, almost all techniques need a supporting layer for the large-area transfer and toThe transfer of monolayer molybdenum disulfide (1L-MoS 2 ) onto any target substrates is inevitable for the next generation of optoelectronic devices such as flexible electronics. However, the existing post-transfer treatments are ineffective for the complete removal of poly(methyl methacrylate) (PMMA) polymer, which is usually used as carrier polymer in the wet-transfer method. The presence of PMMA residues seriously degrades the intrinsic properties of any 2D materials. Several new cleaning methods such as annealing, ozone cleaning, and acetone treatment adopted in this report are found to be ineffective for the complete removal of PMMA residues on the transferred 1L-MoS 2 f...