LEDs are everything, from some of the largest TV screens you can buy, to the types of bulbs that you use in your home. But, not all LED materials are the same. Some are OLEDs or QLEDs, while others are a bit more nuanced. Some don’t even allow you to move electricity through them. It’s this later group that has attracted some intriguing attention from scientists in recent years, and now, a group of researchers working with the Cavendish Laboratory at the University of Cambridge have made an intriguing discovery that could change how we think about LEDs altogether. According to the study, which was published in the journal Nature, scientists have managed to move electricity through tiny insulating particles that aren’t typically capable of conducting electricity. These particles are made up of various elements, including some rare-earth elements such as neodymium and ytterbium, and the breakthrough here could potentially open new doors for LED technology as a whole.
Researchers note that the particles in question, called insulating lanthanide nanoparticles (LnNPs) have been known to shine very brightly when they are placed under light. However, scientists have always struggled to get the particles to actually conduct electricity. Previous attempts to do just that have shown that charges often can’t reach the lanthanide ions inside without extreme heat or voltage.
To bypass this issue, those involved in this new study began looking for a way to hybridize the particles instead. They used 9-ACA organic dye molecules with the LnNPs, letting them replace the surface insulators on the particles, thus allowing them to be charged using a technique known as triplet energy transfer.
How it works
According to the study, the biggest issue that held the LnNPs from being electrically excited is their energy gap. In the past, this limited these particles to only being used in deep-tissue imaging that didn’t rely on electric energy. By replacing the surface insulators, though, the researchers managed to bypass this core problem, thus opening the door to use these particles in more expanded LED operations.
And when the changes were made, the scientists were then able to inject electrons into the organic layer, thus forming what they call “excitons.” From here, the energy is transferred to the lanthanide ions, which allows them to emit an almost completely pure near-infrared (NIR) light, even going so far as to out perform most other organic NIR LEDs in both narrowness and efficiency.
The researchers say that these new LnLEDs open a lot of possibilities for hybrid optoelectronics in biomedical tools. This could allow for better non-bleaching deep imaging applications. Whether this advancement is as huge as previous research that aimed to make X-rays safer or not still remains to be seen, but it does open a lot of new possibilities. The researchers say they still want to improve on the brightness offered by the new hybrid LEDs, but the current method should be easily scalable to other insulators, allowing for even more experimentation.
