Towards light-controlled electronic components

In the future, could our mobile phones and internet data operate using light rather than just electricity? Now, for the first time, an international research team led by CNRS researchers¹ has discovered how to generate an electron gas, found for example in LED screens, by illuminating a material made up of layers of oxides². When the light is switched off, the gas disappears. This phenomenon, which lies at the interface of optics and electronics, paves the way for numerous applications in electronics, spintronics and quantum computing. It is described in an article to be published on 10 October in the journal Nature Materials.

Electronic components that can be controlled by light rather than electricity have the advantage of being much faster, more energy-efficient and simpler to operate: for example, the use of light-controlled transistors could eliminate up to a third of the electrical contacts on a chip, saving around a billion electrical contacts on a computer processor alone.

Other applications combining photonics and electronics could result from this discovery, such as the design of ultra-sensitive optical detectors. In this case, light effectively acts as a "booster": for the same electrical voltage, the current produced is up to 100,000 times stronger than in the dark!

This breakthrough was achieved by combining cutting-edge experiments with theoretical calculations. The arrangement of the atoms at the interface between the two oxide layers was meticulously calibrated, observations at the atomic scale were used to identify the behaviour of the atoms, and modelling helped to describe the motion of their electrons when exposed to light stimuli.

Footnotes

1 - Working at the Albert Fert Laboratory (Laboratoire Albert Fert) (CNRS/Thales). Scientists at the Strasbourg Institute of Materials Physics and Chemistry (Institut de physique et chimie des matériaux de Strasbourg) (CNRS/Université de Strasbourg) and the Solid State Physics Laboratory (Laboratoire de physique des solides) (CNRS/Université Paris-Saclay) were also involved.

2 - These gases, which occur naturally in certain semiconductor materials, had previously only been manipulated using electrical signals in oxidised materials.