2D Materials – The Key to Overcoming Scalability Challenges

Recently, SAIT has been working on the research and development of two-dimensional (2D) materials – crystalline materials with a single layer of atoms. Specifically, the institute has been working on the research and development of graphene, and has achieved groundbreaking research outcomes in this area such as the development of a new graphene transistor as well as a novel method of producing large-area, single-crystal wafer-scale graphene. In addition to researching and developing graphene, SAIT has been working to accelerate the material’s commercialization.

“To enhance the compatibility of graphene with silicon-based semiconductor processes, wafer-scale graphene growth on semiconductor substrates should be implemented at a temperature lower than 400°C.” said Hyeon-Jin Shin, a graphene project leader and Principal Researcher at SAIT. “We are also continuously working to expand the applications of graphene beyond semiconductors.”

2D Material Transformed – Amorphous Boron Nitride

The newly discovered material, called amorphous boron nitride (a-BN), consists of boron and nitrogen atoms with an amorphous molecule structure. While amorphous boron nitride is derived from white graphene, which includes boron and nitrogen atoms arranged in a hexagonal structure, the molecular structure of a-BN in fact makes it uniquely distinctive from white graphene.

Amorphous boron nitride has a best-in-class ultra-low dielectric constant of 1.78 with strong electrical and mechanical properties, and can be used as an interconnect isolation material to minimize electrical interference. It was also demonstrated that the material can be grown on a wafer scale at a low temperature of just 400°C. Thus, amorphous boron nitride is expected to be widely applied to semiconductors such as DRAM and NAND solutions, and especially in next generation memory solutions for large-scale servers.

“Recently, interest in 2D materials and the new materials derived from them has been increasing. However, there are still many challenges in applying the materials to existing semiconductor processes.” said Seongjun Park, Vice President and Head of Inorganic Material Lab, SAIT. “We will continue to develop new materials to lead the semiconductor paradigm shift.”

Exploring Next Generation Battery Technology

Lithium-ion batteries were first commercialized in 1991, and widely applied to markets for mobile devices and electric vehicles. However, with standard lithium batteries requiring charging times of at least an hour to fully charge, even with quick charging technology, and considered to have reached their limit for capacity expansion, there have been numerous attempts to explore use of new innovative materials. Among the materials looked at, graphene has widely become the primary source of interest as the representative next generation material.

In theory, a battery based on the “graphene ball” material requires only 12 minutes to fully charge. Additionally, the battery can maintain a highly stable 60 degree Celsius temperature, with stable battery temperatures particularly key for electric vehicles.

In its research, SAIT sought for an approach to apply graphene, a material with high strength and conductivity to batteries, and discovered a mechanism to mass synthesize graphene into a 3D form like popcorn using affordable silica (SiO2). This “graphene ball” was utilized for both the anode protective layer and cathode materials in lithium-ion batteries. This ensured an increase of charging capacity, decrease of charging time as well as stable temperatures.

Dr. Son In-hyuk, who led the project on behalf of SAIT, said, “Our research enables mass synthesis of multifunctional composite material graphene at an affordable price. At the same time, we were able to considerably enhance the capabilities of lithium-ion batteries in an environment where the markets for mobile devices and electric vehicles is growing rapidly. Our commitment is to continuously explore and develop secondary battery technology in light of these trends.”

SAIT’s research results are covered in-depth in this month’s edition of the science journal Nature Communications in an article entitled, “Graphene balls for lithium rechargeable batteries with fast charging and high volumetric energy densities.” SAIT has also filed two applications for the “graphene ball” technology patent in the US and Korea.

*Graphene is a single layer of carbon atoms from graphite, and is receiving much attention in the battery and display industry due to its physical, chemical stability. Graphene is 100 times more effective than copper in conducting electricity and displays remarkable electron mobility – 140 times faster than silicon – which makes it an ideal material for fast charge.