Page 60 - 2021電子物理系系刊

III.Results and Discussion
A. MoS2 growth
B. MoS2 transfer

1. Wet Transfer
In the conventional method, this is a simple, fast, and capable of realizing
large-area two-dimensional material transfer method. Most MoS2 can be
successfully transferred to substrate. However, the material is prone to wrinkles,
and cracks will appear after removing PMMA. This is because the material floats on
the surface of the aqueous solution and is affected by the surface tension of the
water during the transfer process.

(a) (b)
Figure 5.

2. Dry Transfer
Since the 2D material film is easy to winkle and crack in the water, we put a
layer of heat release tape, that is TRT, on the most surface position. As the outer
layer of support, it has stronger hardness than PMMA, so putting the material in
water can avoid damage caused by surface tension.

(a) (b)
Figure 6.

3. Vibrat on-assist d Transfer
For those MoS2 flake that are highly aligned, we cannot easily transfer them
through the above two methods. So throughout the transfer process, the MoS2 are
exfoliated from the sapphire plays an important factor. We suppose that, the force
between the MoS2 and sapphire is so strong that the material cannot be easily
peeled off. So we apply force through the vibration washing machine to let the 57
material peel off from the sapphire.