A team of scientists has invented the equivalent of body armor for extremely fragile quantum systems, which will make them robust enough to be used as the basis for a new generation of low-energy electronics.
The team created the protective layer by exposing to air a droplet of liquid gallium, which immediately formed a perfectly even layer of gallium oxide on its surface three nanometers thick. By squashing the droplet on top of the 2D material with a glass slide, the gallium oxide layer can be transferred from the liquid gallium onto the material’s entire surface, up to centimeters in scale.
Because this ultrathin gallium oxide is an insulating amorphous glass, it conserves the optoelectronic properties of the underlying 2D semiconductor. The gallium oxide glass can also enhance these properties at cryogenic temperatures and protects well against other materials deposited on top. This allows the fabrication of sophisticated, layered nanoscale electronic and optical devices such as LEDs, lasers, and transistors.
Protection is crucial for thin materials such as graphene that are only a single atom thick — essentially two-dimensional (2D) — and are easily damaged by conventional layering technology. The coating shields against high-energy particles, which would cause a large degree of harm to it, while fully maintaining its optoelectronic properties and its functionality.
Two-dimensional materials have properties such as extremely low resistance or highly efficient interactions with light. Because of these properties, they could play a role in the fight against climate change. Eight percent of global electricity consumption in 2020 was due to information technologies including computers, smartphones, and large data centers. That figure is projected to double every decade.
This work promises lower-energy alternatives for electronics and optoelectronics by harnessing the superior performance of 2D semiconducting materials such as tungsten disulphide, which was used in this study.
Using 2D materials to make more efficient devices will have advantages beyond reduced carbon emissions. 2D technology could also enable efficient sensors on spacecraft or processors in Internet of Things devices that are less limited by battery life.