Researchers from the Albert Fert Laboratory at the French National Centre for Scientific Research (CNRS), in collaboration with scientists from the Institute of Physics and Chemistry of Materials of Strasbourg and the Laboratory of Solid State Physics, have discovered for the first time a method to generate an electron gas — commonly found in LED screens — by illuminating oxide layer materials. This discovery lies at the intersection of optics and electronics, with the related results published in the journal Nature Materials.

Traditionally, electron gases naturally exist in certain semiconductor materials and could previously only be controlled by electrical signals, disappearing once the light source was turned off. This study breaks through that limitation, proving that illuminating oxide layer materials can stably generate an electron gas. This property opens new possibilities for applications in electronics, spintronics, and quantum computing. For example, light-controlled transistors could significantly improve computing efficiency and energy savings by reducing the number of electrical contacts on a chip (potentially saving about one billion contacts on a computer processor).

This achievement was realized through a deep integration of experiments and theoretical calculations. The research team precisely calibrated the atomic arrangement at the interface between two oxide layers through atomic-scale observations and theoretical modeling, revealing the movement patterns of electrons under light stimulation. The discovery also paves the way for the design of ultra-sensitive optical detectors — under illumination, the current generated at the same voltage is enhanced by 100,000 times compared to dark conditions, with light playing a signal amplification role in the process.