Published By : 15 Oct 2018 | Published By : QYRESEARCH
Since graphene, a single-atom-thick material produced from carbon, was discovered in 2003, researchers have gained significant interest in other varieties of 2D materials as well. These 2D materials are of importance to a number of industries as they can stacked together to formulate a variety of devices encompassing several functionalities, including semiconductor properties. In this manner, 2D materials can be used for developing transparent, flexible, and ultra-thin wearables.
However, researchers have found it difficult so far to separate 2D flakes from bulk crystal material for use in the electronics industry, especially on a commercial scale. Existing processes are time-consuming and unreliable, taking up several hours for fabricating material enough for a single device. Now, researchers from MIT have devised a method for 2-inch wafer of a 2D material in time less than an hour. The new method could help realize the possibility of commercialization of a variety of electronic devices using a variety of 2D materials.
The researchers have successfully been able to isolate 2D materials monolayer by monolayer at the wafer scale. The researchers have also shown a way through which these monolayers of 2D materials can be easily stacked up. To reach to this stage, the researchers started by growing a thick stack of 2D material at the top of a sapphire wafer post which a nickel film of 600 nanometer thickness was applied at the top of the stack.
Researchers found that lifting off the nickel film, to which 2D materials adhere more strongly as compared to sapphire, made it easier for separating the entire stack from the wafer. Moreover, it has been found that the force of adhesion between individual layers of 2D material and nickel was stronger than that between the individual layers themselves. Resultantly, when the researchers added another nickel film at the bottom of the stack, it was possible to separate single-atom thick, individual monolayers of the 2D material. Once transferring the first monolayer, assembled by the nickel film, to a substrate is done, the process can be repeated to collect more layers.