Scientists have created a new way to grow high-quality crystalline 2-D materials at scale. This is a major step forward for this technology, as growing the materials at scale has long proven a serious challenge. Perhaps most significantly, this innovation promises to be a game changer when it comes to the future of electronic devices.
Research on this particular subject has become a major priority for scientists ever since the properties of graphene were discovered. Graphene has effectively opened up a whole world of potential in 2-D materials, be they man-made or found in nature. Unfortunately, growing said materials has been no easy task. But now a new multi-step process allows scientists to make single crystals. The crystals are atomically thin films of tungsten diselenide. The film goes across large-area sapphire substrates.
Sapphire is used as the substrate in the process, due to its crystalline structure. The film growth is then oriented in a crystal pattern. This process is known as epitaxy. Material forms in small clumps on the substrate as it is heated, making the clumps spread out across the substrate in a specific pattern. The material creates a large-area film that has no gaps and a minuscule number of defects.
The secret to this new process is a gas-source chemical vapor deposition. It allows scientists to control the island density and rate of spreading. With this unprecedented level of control, scientists can then create a single layer of 2-D material.
This work will prove especially significant in the advancement of industrial-scale electronics. Scientists have learned that there is a powerful interaction between the sapphire substrate and monolayer film. The substrate dominates the properties of the film. In order to compensate for this, scientists grew up to three layers; this led to a performance improvement of anywhere from 20-100 times.
Scientists now have a solid foundational understanding that will allow them to develop device-ready synthetic 2-D semiconductors. Further research into these discoveries is essential, and will no doubt lead to a deeper understanding of 2-dimensional materials and their many possible applications.
