Perovskite LEDs: The soap molecule helps make lighting technology commercially viable

LEDs made of perovskite, titanium, and calcium crystals are potential alternatives to silicon-based ones, but so far have not been able to match them for stability and efficiency.

as if Alex Wilkins

Adding a molecule commonly used in soap to infrared LEDs could make them easier to manufacture, less labor intensive, and display richer colors than currently available.

Solar cells and LEDs made from perovskite, titanium and calcium crystals have been promising to be more efficient and easier to manufacture than conventional silicon-based devices, but making them both stable and efficient has proven difficult to match silicon’s commercial success. .

Now Dawei Di and his colleagues at Zhejiang University in China have developed an infrared perovskite LED device that lasts more than 10,000 hours and is similar in efficiency to conventional silicon LEDs. The next best perovskite LEDs only lasted a few hundred hours before becoming unstable.

“I personally thought it was impossible before we saw our LEDs working flawlessly for months,” says Dee. But now we think OK, near-infrared perovskite LEDs can last a very long time.

The key to this improved stability is the introduction of a molecule called sulfobetaine 10 (SFB10), which is commonly used as a detergent. The molecule attracts positive and negative ions that move freely within the perovskite crystal structure and destabilize it. But with SFB10, the ions are prevented from moving.

“If we don’t use this dipolar molecular stabilizer, the ions can move and the structure of the perovskite can change…Eventually, those that are completely useless for light emission, such as lead iodide and other organic compounds, will decompose.”

Although infrared LEDs are not suitable for ordinary lighting, it should be possible to apply similar methods to produce visible light LEDs. “There shouldn’t be any problem in principle for us to get the same stability results for green and red,” says Dee, although blue light can be more difficult.

The efficiency and stability of this new perovskite cell is remarkable, says Kyle Frona at the University of Cambridge. “I think this kind of approach should be tested immediately in some visible LEDs because it’s very promising,” he said.

Journal Reference: Nature photonicsDOI: 10.1038/s41566-022-01046-3