Investigation of uniaxial and biaxial strains on the band gap modifications of monolayer MoS2 with tight-binding method

Shahriari, Majid; Dezfuli, Abdolmohammad Ghalambor; Sabaeian, Mohammad

doi:10.1016/j.spmi.2018.10.001

Cited by 7 publications

(3 citation statements)

References 32 publications

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“…Consequently, the incorporation of biaxial strain can tune the optical and electronic properties more effectively. − The biaxial strain has a greater effect than the uniaxial one on the K-Q valley separation (Δ E QK ) in the electronic band structure, which is known to control electron–phonon intervalley scattering and therefore electron mobility. The greater change in Δ E QK with biaxial tensile strain can provide a higher mobility improvement than the uniaxial strain. − The strain engineering methods used in Si technology present major hurdles for the development of 2D material-based transistors. Specifically, techniques such as heteroepitaxial growth or deposition of a stressor, which are essential for generating strains through lattice mismatches, are unsuitable for application at the atomic level thickness of 2D materials .…”

Section: Introductionmentioning

confidence: 99%

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS₂ Thin Film Transistors

Shin,

Katiyar,

Hoang

et al. 2024

ACS Nano

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Strain engineering has been employed as a crucial technique to enhance the electrical properties of semiconductors, especially in Si transistor technologies. Recent theoretical investigations have suggested that strain engineering can also markedly enhance the carrier mobility of two-dimensional (2D) transition-metal dichalcogenides (TMDs). The conventional methods used in strain engineering for Si and other bulk semiconductors are difficult to adapt to ultrathin 2D TMDs. Here, we report a strain engineering approach to apply the biaxial tensile strain to MoS 2 . Metal-organic chemical vapour deposition (MOCVD)-grown large-area MoS 2 films were transferred onto SiO 2 /Si substrate, followed by the selective removal of the underneath Si. The release of compressive residual stress in the oxide layer induces strain in MoS 2 on top of the SiO 2 layer. The amount of strain can be precisely controlled by the thickness of oxide stressors. After the transistors were fabricated with strained MoS 2 films, the array of strained transistors was transferred onto plastic substrates. This process ensured that the MoS 2 channels maintained a consistent tensile strain value across a large area.

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Section: Introductionmentioning

confidence: 99%

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS₂ Thin Film Transistors

Shin,

Katiyar,

Hoang

et al. 2024

ACS Nano

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“…To overcome such inherent limitation of graphene, two-dimensional layered semiconductor materials, such as transition metal dichalcogenides (TMDCs), with wide range adjustable band gaps have been considered [18][19][20]. The TMDCs with the MX2 formula, where M is a metal intermediate and X is a chalcogen, are studied by many groups due to their unique mechanical, thermal, electrical, and optoelectronic properties [21][22][23][24]. From different types of TMDCs, the structures that (M=W, Mo) and (X=S, Se, Te) have indirect and direct band gaps at their bulk and monolayer structures, respectively [25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Orbital characteristics and Oscillator strength in bulk, bilayer, and monolayer MoS2: A comparison study

Mansouri,

Dezfuli,

Salehi

2024

Preprint

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In this article, the orbital characters and the oscillator strength of MoS2 in the bulk, monolayer, and bilayer structures have been studied and compared. The orbital characters are key parameters in determining the distribution and specifications of electrons in materials. The oscillator strength is also a quantity that represents the probability of electric dipole transitions. Here, the calculations of these parameters have been performed using the pseudopotential method based on density functional theory with generalized gradient approximation. For the bilayer structure, the calculations are based on the van der Waals corrected DFT. Using the results of the partial density of states obtained from the density functional theory, the orbital characters of all three structures are extracted. In addition, the oscillator strength has been derived from the matrix elements of the momentum operator using the first principles method. The results of orbital character and oscillator strength for bilayer and bulk are similar and completely different from those of the monolayer. Such similarities in orbital character and oscillator strength for the bulk and bilayer could be related to the fact that they belong to the point groups with the same symmetry characteristics. Accordingly, the difference in orbital character and oscillator strength of the monolayer MoS2 could be because the monolayer has a point group with different symmetry characteristics. Both bulk and bilayer structures belong to the D6h and D3d points groups with inversion center symmetry called centrosymmetric, and the monolayer belongs to the D3h points group without the inversion symmetry, named noncentrosymmetric.

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“…Consequently, strain engineering has become a useful tool for tuning the photoelectric properties of MoS 2 . Theoretical studies have analyzed the influence of strain on the properties of monoor multilayer MoS 2 using first-principles calculations based on density functional theory (DFT), such as structure, [20,21] bandgap, [22] electronic and vibrational properties, [23] and thermoelectric performance. [24] Meanwhile, the experimental work is also carrying on to mutually verify with the calculating results.…”

Section: Introductionmentioning

confidence: 99%

Strain Tune Suspended MoS₂ for Polarization Photodetection

Liu

Jiang

Tan

et al. 2023

Physica Rapid Research Ltrs

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In situ modulation of molybdenum disulfide (MoS2) structure and breaking its isotopic optical property are crucial for fabricating high‐performance multidimensional photodetectors. However, achieving this remains a challenge. Herein, by introducing a cavity in the channel, the strain tunable suspended MoS2 phototransistor is fabricated. By pumping the environment, a pressure difference between the environment and cavity is generated, inducing strain in the MoS2. Simulation reveals the strain can be tuned up to 0.598% by changing environment pressure. The electrical and photoelectrical properties exhibit significant tuning in response to pressure. During this experiment, the conductance of MoS2 under different pressures shows considerable differentiation between 50 and 100 kPa. As light wavelength decreases, the trend of photocurrent increasing under different pressure becomes more apparent. The differential conductance–voltage curve of different wavelengths at 10 Pa is more dispersed than that at 101 kPa. Those results demonstrate the coupling effect between light and strain. Interestingly, the symmetric photoelectrical property of MoS2 can be broken, resulting in polarization detection. At a pressure of 60 kPa, the dichroic ratio reaches 1.38, similar to intrinsic anisotropic two‐dimensional materials. This can be attributed to the breaking of symmetric structure caused by strain.

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Investigation of uniaxial and biaxial strains on the band gap modifications of monolayer MoS2 with tight-binding method

Cited by 7 publications

References 32 publications

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS₂ Thin Film Transistors

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS₂ Thin Film Transistors

Orbital characteristics and Oscillator strength in bulk, bilayer, and monolayer MoS2: A comparison study

Strain Tune Suspended MoS₂ for Polarization Photodetection

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Investigation of uniaxial and biaxial strains on the band gap modifications of monolayer MoS2 with tight-binding method

Cited by 7 publications

References 32 publications

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS2 Thin Film Transistors

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS2 Thin Film Transistors

Orbital characteristics and Oscillator strength in bulk, bilayer, and monolayer MoS2: A comparison study

Strain Tune Suspended MoS2 for Polarization Photodetection

Contact Info

Product

Resources

About

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS₂ Thin Film Transistors

Nonconventional Strain Engineering for Uniform Biaxial Tensile Strain in MoS₂ Thin Film Transistors

Strain Tune Suspended MoS₂ for Polarization Photodetection