These 2D materials, which are only a few atoms thick, are able to carry electric charge extremely efficiently, heralding major performance gains for next-generation electronics. However, until now integrating 2D materials into devices and systems like computer chips has proven difficult.
Conventional manufacturing techniques for microchips that rely on the use of chemicals, high temperatures, or destructive processes like etching, can easily damage them. But a team of researchers led by MIT have developed a new technique to integrate 2D materials into devices in a single step while ensuring the surfaces of the materials and the resulting interfaces remain pristine and undamaged.
Their method allows the 2D material to be physically stacked onto other pre-built device layers, and because the 2D material remains undamaged, the 2D materials’ unique optical and electrical properties can be fully explored. According to MIT, the new technique is versatile enough to be used with many materials, and could have diverse applications in high-performance computing, sensing, and flexible electronics.
In order to unlock the materials new functionalities, the research team needed to form clean interfaces held together by the van der Waals force, a naturally occurring force that binds together atoms and molecules that are in close proximity to one another. However, relying on van der Waals integration of materials into fully functional devices has challenges, says Farnaz Niroui, MIT assistant professor of electrical engineering and computer science (EECS), and senior author of a new paper describing the research.
Niroui said: “Van der Waals integration has a fundamental limit,” she explains. “Since these forces depend on the intrinsic properties of the materials, they cannot be readily tuned. As a result, there are some materials that cannot be directly integrated with each other using their van der Waals interactions alone.
“We have come up with a platform to address this limit to help make van der Waals integration more versatile, to promote the development of 2D-materials-based devices with new and improved functionalities.”
Niroui wrote the paper alongside fellow researchers at MIT, Boston University, National Tsing Hua University in Taiwan, the National Science and Technology Council of Taiwan, and National Cheng Kung University in Taiwan.
The researchers used the new technique to create p-type transistors, which are generally challenging to make with 2D materials. According to MIT, the transistors made by the research team have improved on previous studies, and can provide a platform toward studying and achieving the performance needed for practical electronics.