Illustration of the graphene-GaSe heterojunction.
Illustration of the graphene-GaSe heterojunction.

Researchers from Aalto University in Finland have found a way to fabricate a novel electricity-conducting material by merging the one atom-thick sheets of carbon known as graphene with gallium selenide (GaSe), another two-dimensional (2D) material. This creates an interface between the two crystalline 2D materials known as a heterojunction, potentially allowing this 2D structure to form the basis for a new generation of electronic devices. The results were recently published in Advanced Materials.

“This is the first time when gallium selenide is used with graphene,” says Juha Riikonen, head of the research group. “This kind of new heterojunctions will be important in future as conventional heterojunctions are already vital part of current semiconductor industry forming the basis for example for lasers and transistors.”.

“Because the component is made of 2D materials, it is, in comparison with those containing silicon, extremely thin, approximately one ten-thousandth part of the diameter of a single hair,” explains post-doctoral researcher Wonjae Kim.

In earlier research, 2D structures made from graphene and GaSe were fabricated manually, layer by layer, which made the process slow, challenging and difficult to scale. In contrast, Riikonen, Kim and their colleagues were able to take advantage of standard fabrication methods utilized by the semiconductor industry to produce their 2D structure.

“Our inspiration comes from the existing silicon technology and we want to bring out the state-of-the-art fabrication of 2D material devices from research labs to industry,” says Kim. “In addition to new and simpler way of manufacturing, our components have excellent characteristics. For example, the on/off ratio, which is critical parameter in electronics, is over 10³. This underscores the feasibility of both GaSe and the device concept.

“Being transparent and thin, 2D components open completely new possibilities for the development of electronics,” he predicts. “They would be suitable for example for wearable electronics, and they could be placed on spectacles and windows. Moreover, the components are suitable for various sensors.”

This story is adapted from material from Aalto University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.