Preparing method of two-dimensional materials with controlled number of layers
AssigneeAjou University Industry-Academic Cooperation Foundation
InventorsJaehyun Lee, Jiyun Moon
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Abstract
The present disclosure relates to a preparing method of two-dimensional materials with a controlled number of layer including depositing a metal thin film on a surface of a bulk material; exfoliating a two-dimensional material from the surface of the bulk material together with the metal thin film; and transferring the two-dimensional material onto a substrate, in which the number of layers of the two-dimensional material to be exploited is controlled by controlling an internal stress of the metal thin film.
Claims9
A preparing method of a two-dimensional material with a controlled number of layers comprising:
- depositing a metal thin film on a surface of a bulk material;
- exfoliating a two-dimensional material from the surface of the bulk material together with the metal thin film;
- and
- transferring the two-dimensional material onto a substrate,
- wherein the number of layers of the two-dimensional material to be exfoliated is controlled by controlling an internal stress of the metal thin film,
- wherein the internal stress σf of the metal thin film is represented by the following Equation 1 and when a total accumulated strain energy UTotal represented by the following Equation 2 reaches a binding energy γ between the two-dimensional materials, the two-dimensional material is exfoliated,
- σ
- f
- =
- γ
- U
- Total
- [
- Equation
-
- 1
- ]
- wherein in Equation 1, γ is a binding energy of a two-dimensional material and UTotal is a total accumulated strain energy,
- U
- Total
- =
- (
- 1
- -
- v
- f
- )
- 2
-
- Y
- f
-
- t
- f
-
- σ
- f
- 2
- +
- (
- 1
- -
- v
- s
- )
- 2
-
- Y
- s
-
- t
- f
- 2
- t
- s
-
- σ
- f
- 2
- [
- 12
-
- (
- d
- spall
- t
- s
- )
- 3
- -
- 24
-
- (
- d
- spall
- t
- s
- )
- 2
- +
- 16
-
- (
- d
- spall
- t
- s
- )
- ]
- [
- Equation
-
- 2
- ]
- wherein in Equation 2, vs and vf are Poisson's ratios of a bulk material and a metal thin film, respectively, Ys and Yf are Young's modulus of a bulk material and a metal thin film, respectively, ts and tf are thicknesses of a bulk material and a metal thin film, respectively, and dspall is a spall depth.
Dependencies are inferred from the claim text.