Japanese researchers at the National Institute for Materials Science and Shinshu University have developed a way to shrink capacitors — key components that store energy — further, which could accelerate the development of more compact, high-performance next-gen electronic devices. The study appears in the journal ACS Nano.

Takayoshi Sasaki and colleagues note that current technology has almost reached its limit in terms of materials and processing, which in turn limits the performance that manufacturers can achieve. In response, researchers have gone to the nanoscale, but “nanocapacitors” are not easy to make. They require harsh, difficult-to-use methods and even then, they may not work that well.

Layers of different types of oxide nanosheets

So Sasaki’s team developed an easier way to make high-performance “ultrathin” capacitors. The researchers found that they could use gentle techniques and mild conditions to create a sandwich consisting of layers of two different types of oxide nanosheets to produce an ultrathin capacitor.

In addition, the new capacitor has a capacitance density of as high as ∼27.5 μF (microfarads) per square centimeter, which is approximately 2000 times higher than those of currently available commercial products.

The fabrication process, involving layer-by-layer assembly of the nanosheets without costly fabrication lines and special annealing processes for metal electrode layers is another big beneﬁt. Furthermore, the all-nanosheet capacitors can be readily assembled on plastic or ﬂexible substrates.

Better than graphene

The researchers say that, in the future, the ultrathin capacitors could be used in printed circuit boards and in DRAM memory storage devices, for example. They also speculate that “the virtually inﬁnite varieties of oxide nanosheets, which can be used to assemble various nanosheet architectures, suggest that 2D heterointerfaces will oﬀer an unprecedented versatility for the realization of new 2D states and molecularly thin ﬁlm devices even beyond graphene.”

The authors acknowledge funding from the Japan Science and Technology Agency and MEXT, Japan.

Abstract of ACS Nano paper