Insulating oxides are non-conductive oxygen-containing compounds, but they can sometimes create conductive interfaces when they are correctly layered together. Conductive electrons at the interface form a two-dimensional electron gas (2DEG) with exotic quantum properties that make the system useful in electronic and light quantum applications.
Researchers at Yale University have developed a 2DEG system on gallium arsenide, an efficient semiconductor that absorbs and emits light.
This development promises new electronics that interact with light, such as new transistors, superconductor switches, and gas sensors.
Lior Kornblum, now at the Technion Institute of Technology, Israel, who describes the new research that appears in the Journal of Applied Physics, says, “I consider this to be the premise for oxide-electronics devices.”
The researchers were surprised to find that in the 2DEG system, a combination of two insulating oxide layers can produce conductive electrons that behave like a gas or liquid between layers of oxide and can transmit information.
Researchers have previously observed 2DEG with semiconductors, but 2DEG oxide has a much higher electron density, making them more potential for some electronic applications.
2DEG oxide has attractive quantum properties. For example, this system appears to exhibit an easy combination with magnetic materials and high superconductivity.
In general, it isn’t very easy to produce 2DEG oxide in large quantities because only the necessary pieces of oxide crystals can be produced. However, if researchers can develop oxides on sheets of commercial semiconductor materials, they can expand 2DEG oxide for real-world applications.
Developing 2DEG oxide on semiconductors also allows researchers to integrate material structures with conventional electronics better. According to Kornblum, oxide electronic circuits interacting with electrons in semiconductors could create new functions and be widely applied in a wider range of devices.