Mechanical Properties of 2D Materials Studied by In Situ Microscopy Techniques

Li, Xing; Sun, Mei; Shan, Chongxin; Qing, Chen; Wei, Xianlong

doi:10.1002/admi.201701246

Cited by 89 publications

(75 citation statements)

References 200 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…While the electrical and optical properties of 2D materials can be explored with conventional experimental tools developed to test 3D materials and thin film devices, probing the mechanical properties of 2D materials is more challenging, as neither bending nor tensile test macroscopic setups can be employed. Nanoindentation, the analysis of the dynamics of nanomechanical resonators, and the microscopic adaptation of tensile tests setups or Brillouin scattering have been developed to characterize the fundamental mechanical properties of 2D materials such as their Young's modulus . Although powerful, these techniques require dedicated setups and rather complex data acquisition and/or analysis.…”

Section: Summary Of Values For the Young's Modulus (And Their Uncertamentioning

confidence: 99%

Revisiting the Buckling Metrology Method to Determine the Young's Modulus of 2D Materials

et al. 2019

View full text Add to dashboard Cite

Nanoindentation, [2,[6][7][8] the analysis of the dynamics of nanomechanical resonators, [9] and the microscopic adaptation of tensile tests setups [10] or Brillouin scattering [11] have been developed to characterize the fundamental mechanical properties of 2D materials such as their Young's modulus. [12,13] Although powerful, these techniques require dedicated setups and rather complex data acquisition and/or analysis. Alternative to these methods, Stafford et al. [14] introduced the buckling metrology method, a simple and elegant way to measure the Young's modulus of thin polymeric films by studying the buckling instability, which arises when the film is deposited onto a compliant substrate, and it is subjected to uniaxial compression. [15] Under these conditions, the trade-off between the adhesion forces between film and substrate and the bending rigidity of the film leads to a rippling of the thin film with a characteristic wavelength that only depends on the elastic properties of the film and the substrate. This elegant method to characterize the mechanical properties of thin films has been extensively used to study coatings [14] and organic semiconducting materials. [16] However, it has been scarcely employed to study 2D materials, [17][18][19][20] and it seems that is has been mostly overlooked by the 2D materials community.Here, we apply the buckling-based metrology method to determine the Young's modulus of transition metal dichalcogenide (TMDC) flakes with thickness ranging from 2 layers up to 10 layers. We use optical microscopy to determine both the number of layers and the rippling wavelength, which is therefore very fast and simple to implement. We critically compare the results obtained with this method and demonstrate that despite its simplicity it provides results in good agreement with other techniques to study the mechanical properties of 2D materials. We believe that the buckling-based metrology method provides a fast route to determine the Young's modulus of 2D materials, being an excellent alternative to other existing nanomechanical test methods that are more technically demanding.The samples are fabricated by mechanical exfoliation of bulk layered TMDC crystals with adhesive tape (see Experimental Section for details). The exfoliated material is then transferred onto a compliant elastomeric substrate (Gel-Film, a commercially available polydimethylsiloxane, PDMS, film manufactured by Gel-Pak) which is subjected to a uniaxial stress of ≈20%. Right after the transfer, the stress on the elastomeric Measuring the mechanical properties of 2D materials is a formidable task. While regular electrical and optical probing techniques are suitable even for atomically thin materials, conventional mechanical tests cannot be directly applied. Therefore, new mechanical testing techniques need to be developed. Up to now, the most widespread approaches require micro-fabrication to create freely suspended membranes, rendering their implementation complex and costly. Here, a simple yet powerful technique is ...

show abstract

Section: Summary Of Values For the Young's Modulus (And Their Uncertamentioning

confidence: 99%

Revisiting the Buckling Metrology Method to Determine the Young's Modulus of 2D Materials

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Figure shows the broad catalogue of 2D materials with varying bandgap utilized for various applications in different wavelength regimes. Specifically, research and development of 2D materials like transition‐metal dichalcogenides (TMDCs) and black phosphorus have progressed rapidly due to their excellent mechanical properties, which have played extensive roles in designing flexible and stretchable next‐generation electronic devices . These materials have attracted much attention not only due to their semiconducting nature, but also due to their ultralight weight, high Young's modulus, and high tensile strength.…”

Section: Introductionmentioning

confidence: 99%

The Role of Graphene and Other 2D Materials in Solar Photovoltaics

et al. 2018

View full text Add to dashboard Cite

2D materials have attracted considerable attention due to their exciting optical and electronic properties, and demonstrate immense potential for next-generation solar cells and other optoelectronic devices. With the scaling trends in photovoltaics moving toward thinner active materials, the atomically thin bodies and high flexibility of 2D materials make them the obvious choice for integration with future-generation photovoltaic technology. Not only can graphene, with its high transparency and conductivity, be used as the electrodes in solar cells, but also its ambipolar electrical transport enables it to serve as both the anode and the cathode. 2D materials beyond graphene, such as transition-metal dichalcogenides, are direct-bandgap semiconductors at the monolayer level, and they can be used as the active layer in ultrathin flexible solar cells. However, since no 2D material has been featured in the roadmap of standard photovoltaic technologies, a proper synergy is still lacking between the recently growing 2D community and the conventional solar community. A comprehensive review on the current state-of-the-art of 2D-materials-based solar photovoltaics is presented here so that the recent advances of 2D materials for solar cells can be employed for formulating the future roadmap of various photovoltaic technologies.

show abstract

“…During the growth of ternary nitride alloy samples, the atomic ordering always happens, and this effect can have a significant influence on the bandgap, optical properties, and carrier transport properties of the III-N alloys. [7][8][9][10] The optical properties of III-N compounds can be strongly influenced by the nearest-neighbor scale distribution fluctuations, due to the exciton localization as their intrinsic property. The spontaneous formation of ordering is still not well-understood due to the sophisticated nature of these growth processes occurring far from equilibrium conditions, but this effect has often been regarded as a kinetically limited growth surface-induced process.…”

Section: Introductionmentioning

confidence: 99%