Chinese scientists develop ultra-stable perovskite LEDs

HEFEI, June 14 (Xinhua) -- Chinese researchers have achieved a major breakthrough in extending the lifespan of perovskite light-emitting diodes (LEDs), according to the University of Science and Technology of China.

A team from the university, led by Professor Xiao Zhengguo, has developed a novel approach to fabricating all-inorganic perovskite films featuring larger crystal grains and enhanced heat resistance. This successfully increased the LED brightness to over 1.16 million nits and extended the operational lifespan beyond 180,000 hours.

This breakthrough technology not only successfully overcomes the longstanding technical bottleneck where perovskite LEDs struggled to simultaneously achieve high efficiency and stability, but also holds significant promise for future widespread application in high-end displays and ultra-high-brightness lighting, according to Xiao.

The research findings have been published in the journal Nature.

Perovskite is a high-performance novel material prized for its high luminous efficiency, low cost, and processing flexibility, holding broad application potential in solar cells, LEDs, and photodetectors.

However, in traditional perovskite materials, electrons and holes -- the charge carriers responsible for light emission -- struggle to collide efficiently to produce light.

Researchers used to create very small nanoparticles or ultra-thin material layers to boost luminous efficiency. A significant drawback of this approach was the difficulty in achieving high brightness for LEDs, coupled with short lifespans typically lasting only a few hours, hindering practical applications.

To overcome this challenge, the research team proposed a fundamentally different strategy. By adding specific compounds into the perovskite material and employing a high-temperature annealing process, they produced a new type of perovskite film characterized by larger crystal grains and fewer defects.

This novel material exhibits greater internal order, significantly enhancing LED stability and brightness, Xiao said.

The study revealed that this new perovskite LED achieves a luminous efficiency exceeding 22 percent, on par with that of commercial display products. Compared to mainstream commercial OLED or LED screens currently on the market, the new perovskite LED boasts an extreme brightness reaching 1.16 million nits.

As the peak brightness of displays used in daily life typically falls within several thousand nits, calculating at a normal brightness level of 100 nits, the new perovskite LED has a theoretical lifespan exceeding 180,000 hours. This already meets the broad standards required for commercial LED products. ■