Scientists have discovered how to electrically power insulating nanoparticles using molecular antennas, creating exceptionally pure near-infrared LEDs with wide-ranging potential.

A newly developed approach uses “molecular antennas” to direct electrical energy into nanoparticles that normally cannot conduct electricity. This advance has led to a completely new category of ultra-pure near-infrared LEDs designed for uses in medical diagnostics, optical communication systems, and sensing technologies.

Researchers at the Cavendish Laboratory, University of Cambridge have discovered a way to electrically activate insulating nanoparticles, something that had been considered unachievable under standard conditions. By attaching organic molecules that function like miniature antennas, the team successfully produced the first light-emitting diodes (LEDs) based on these particles. The findings, reported in Nature, introduce a pathway for next-generation devices that could support deep-tissue medical imaging and high-speed data transfer.

The research centers on lanthanide-doped nanoparticles (LnNPs), a group of materials known for generating extremely pure and stable light. Their emission is especially strong in the second near-infrared range, which can move through dense biological tissue. Despite these advantages, their lack of electrical conductivity has long prevented them from being integrated into electronic components such as LEDs.

“These nanoparticles are fantastic light emitters, but we couldn’t power them with electricity. It was a major barrier preventing their use in everyday technology,” said Professor Akshay Rao, who led the research at the Cavendish Laboratory. “We’ve essentially found a back door to power them. The organic molecules act like antennas, catching charge carriers and then ‘whispering’ it to the nanoparticle through a special triplet energy transfer process, which is surprisingly efficient.

A Clever Hybrid Approach

The researchers addressed the problem by developing a hybrid material that combines organic and inorganic components. They attached an organic dye containing a functional anchoring group, known as 9-anthracenecarboxylic acid (9-ACA), to the outer surface of the LnNPs. In the LEDs they built, electrical charges are directed into the 9-ACA molecules, which act as molecular antennas instead of sending the charges directly into the nanoparticles.

Once energized, these molecules move into an excited triplet state. In many optical systems this triplet state is regarded as “dark” and typically goes unused. In this design, however, more than 98 percent of the energy from the triplet state is passed to the lanthanide ions within the insulating nanoparticles, producing a bright and efficient emission.

This new method allows the team’s “LnLEDs” to be turned on with a low operating voltage of around 5 volts and to produce electroluminescence with an exceptionally narrow spectral width, making it significantly purer than that of competing technologies like quantum dots (QDs).

“The purity of the light in the second near-infrared window emitted by our LnLEDs is a huge advantage,” said Dr Zhongzheng Yu, a lead author of the study and postdoctoral research associate at the Cavendish Laboratory. “For applications like biomedical sensing or optical communications, you want a very sharp, specific wavelength. Our devices achieve this effortlessly, something that is very difficult to do with other materials.”

Biomedical, Communication, and Sensing Applications

This discovery unlocks a wide range of potential applications. With their ability to emit exceptionally pure light when powered electrically, these nanoparticles could enable the development of next-generation medical devices.

Tiny, injectable, or wearable LnLEDs could be used for deep-tissue imaging to detect diseases like cancer, monitor organ function in real-time, or activate light-sensitive drugs with pinpoint precision. The purity and narrow spectral width of the emitted light also hold promise for faster, clearer optical communications systems, potentially allowing more data to be transmitted with less interference. The technology could also lead to highly sensitive devices for detecting specific chemicals or biological markers.

The team has already demonstrated a peak external quantum efficiency of over 0.6% for their NIR-II LEDs, an extremely promising result for a first-generation device, and has identified clear strategies for further improvement.

“This is just the beginning. We’ve unlocked a whole new class of materials for optoelectronics,” added Dr Yunzhou Deng, postdoctoral research associate at the Cavendish Laboratory. “The fundamental principle is so versatile that we can now explore countless combinations of organic molecules and insulating nanomaterials. This will allow us to create devices with tailored properties for applications we haven’t even thought of yet.”

Reference: “Triplets electrically turn on insulating lanthanide-doped nanoparticles” by Zhongzheng Yu, Yunzhou Deng, Junzhi Ye, Lars van Turnhout, Tianjun Liu, Alasdair Tew, Rakesh Arul, Simon Dowland, Yuqi Sun, Xinjuan Li, Linjie Dai, Yang Lu, Caterina Ducati, Jeremy J. Baumberg, Richard H. Friend, Robert L. Z. Hoye and Akshay Rao, 19 November 2025, Nature.
DOI: 10.1038/s41586-025-09601-y

This work was supported in part by a UK Research and Innovation (UKRI) Frontier Research Grant (EP/Y015584/1) and Postdoctoral Individual Fellowships (Marie Skłodowska-Curie Fellowship grant scheme).

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