USTC has developed a perovskite single crystal LED with a lifespan of 12,500 hours

Professor Xiao Zhengguo's research group at the School of Physics at the University of Science and Technology of China used the space confinement method to grow high-quality, large-area, ultra-thin perovskite single crystals, and for the first time prepared perovskite single crystal light-emitting diodes (LEDs) with a brightness of more than 86,000 candelas/square meter and a lifespan of up to 12,500 hours, taking an important step towards the application of perovskite LEDs in human lighting. Relevant results were recently published in Nature Photonics.

Currently, the external quantum efficiency of perovskite LEDs based on polycrystalline films has exceeded 20%, which is comparable to commercial organic LEDs. In recent years, the lifetimes of the vast majority of reported high-efficiency perovskite LED devices range from hundreds to thousands of hours, still lagging behind organic LEDs.

Factors such as ion movement, uneven carrier injection, and Joule heat generated during operation will affect device stability. In addition, severe Auger recombination in polycrystalline perovskite devices also limits the brightness of the devices.

In response to these problems, Xiao Zhengguo's research team used the space confinement method to grow perovskite single crystals in situ on the substrate. Then, by regulating the growth conditions and introducing organic amines and polymers, the crystal quality was effectively improved, thus preparing high-quality perovskite thin single crystals with a minimum thickness of only 1.5 microns, a surface roughness of less than 0.6 nanometers, and an internal fluorescence quantum yield of 90%. Using a thin single crystal as the light-emitting layer, the researchers prepared a perovskite single crystal LED device with an external quantum efficiency of 11.2%, a brightness of more than 86,000 candelas/square meter, and a lifespan of up to 12,500 hours.

This means that perovskite single crystal LED has initially reached the commercialization threshold and has become one of the most stable perovskite LED devices currently.