Atom-thin sheets of materials, known as two-dimensional (2D) materials, have attracted significant interest due to their unique properties and potential applications in various fields. However, controlling the growth and properties of these materials has been a challenging task.
Now, researchers at the University of Manchester have demonstrated a new method for growing 2D materials on specially designed cone-shaped substrates, which enables precise control over the formation and properties of defects in the material.
The team, led by Professor Sir Kostya Novoselov, used a chemical vapor deposition (CVD) technique to grow hexagonal boron nitride (h-BN) on cone-shaped substrates made of silicon dioxide. By carefully controlling the growth conditions, they were able to achieve a uniform and conformal coverage of h-BN on the cones, with the desired density and distribution of defects.
The researchers found that the cone-shaped substrate promotes the formation of specific types of defects, such as triangular and hexagonal holes, while suppressing the formation of other types of defects. This control over defect formation is crucial for optimizing the properties of 2D materials for specific applications.
The ability to control defects in 2D materials is important for several reasons. Defects can affect the electrical, optical, and mechanical properties of the material, and they can also serve as nucleation sites for further defects. By controlling the density and distribution of defects, researchers can tailor the properties of 2D materials for specific applications.
For example, in the case of h-BN, controlling defects is important for improving its insulating properties, which are crucial for its use in electronic devices. By reducing the density of defects, the researchers were able to significantly enhance the insulating properties of h-BN grown on cone-shaped substrates.
The new method developed by the Manchester researchers provides a powerful tool for controlling the growth and properties of 2D materials, which could open up new possibilities for the development of advanced electronic, optoelectronic, and mechanical devices.
