Scientists design new coating for rare earth materials to glow when powered by electricity

BEIJING -- A research team has found a way to make certain rare earth materials, known for their bright and stable light, emit light when powered directly by electricity.

The study, co-conducted by researchers from Heilongjiang University, Tsinghua University, and the National University of Singapore, has been published in the latest issue of Nature.

Rare earth nanocrystals are already used in some lighting applications due to their pure colors and high efficiency. However, they are naturally insulating, meaning electric current cannot pass through them easily. As a result, they have not been widely used in modern electric-driven devices like LEDs and OLEDs.

"It's like trying to run while wearing a heavy winter coat," said Han Sanyang, an associate professor at Tsinghua University. "The insulating nature of these materials makes it very hard for electricity to reach and activate their glow."

To solve this, the team designed a special molecular coating that acts like an "energy-conversion layer." This layer wraps around each nanocrystal, capturing electrical energy and efficiently transferring it to the rare earth elements within, which then emit light.

This new approach allows the nanocrystals to produce adjustable, high-purity colors of light using electricity, Han said.

"The research opens the door to using these materials in scenarios such as human health monitoring, non-invasive testing, and even crop supplemental lighting technology," he added.

The research team is now working to further improve the technology, especially for healthcare and infrared applications.