Up to date! Ultra-thin diamond films can be made from graphene without high pressure!
According to foreign media reports, although graphene is only one atom thick, its strength must be heard by everyone, but how can there be any way to make it stronger? -Turn it into pieces of diamond. South Korean researchers have now developed a way to convert graphene into the thinnest diamond film without the use of high pressure.
Graphene, graphite, and diamond are all made of the same material, carbon, but the difference between these materials is the arrangement and combination of carbon atoms. Graphene is a carbon layer that is only one atom thick, with strong horizontal bonds between them. Graphite is a layer of graphene sheets stacked on top of each other. Each layer has a strong bond inside, and different layers are connected by weak bonds. In diamond, carbon atoms are tightly connected in three dimensions to form an incredibly hard material.
When the bonding between graphene layers is strengthened, it turns into a 2D form of diamond called diamane. The problem is that it is usually done that way. One method requires extremely high pressure, and once the pressure is gone, the material is reduced to graphene. Other studies need to add hydrogen atoms to graphene, but this makes it difficult to control the bonds.
In this new study, researchers from the Institute of Basic Sciences (IBS) and the Ulsan National Institute of Science and Technology (UNIST) replaced hydrogen with fluorine. Their idea was to expose the double-layer graphene to fluorine atoms, in this way to make the two layers of graphene more tightly bound together to form a stronger chemical bond.
The research team first used a reliable method of chemical vapor deposition (CVD) to prepare double-layer graphene on copper and nickel substrates. They then exposed the graphene to the steam of xenon difluoride. At this time, the fluorine atoms in the mixture will adhere to the carbon atoms, thereby strengthening the bonding between the graphene layers and forming a layer of ultra-thin fluorinated diamond, F-diamane.
The new process is much simpler than other processes in the past, which should make it relatively easy to scale. Ultra-thin diamond can be made stronger, smaller, and more flexible electronic components, especially as wide-gap semiconductors.
The study's lead author, Pavel V. Bakharev, pointed out that this simple fluorination method can work at near room temperature and low pressure without the use of plasma or any gas activation mechanism, so this greatly reduces the possibility of defects.
Related research reports have been published in Nature Nanotechnology.