Scientists prepare large-area sky blue perovskite LED

Professor Xiao Zhengguo's research group from the University of Science and Technology of China recently successfully fabricated a large-area, high-efficiency sky blue perovskite LED by means of a blade coating method, which is an important step towards the commercial application of perovskite LED lighting. The related results were published in Advanced Materials on February 18.

Metal halide perovskite LEDs have good electrical conductivity and can achieve high luminous brightness at lower voltages, making them ideal candidates for next-generation energy-saving lighting. Currently, red and green perovskite LEDs are highly efficient, but sky-blue/blue-light perovskite LEDs, which are essential in white lighting, are less efficient, mainly due to the more difficult crystallization process of sky-blue/blue-light perovskite films. Control resulting in poor film quality. Previously, there have been no reports on the preparation of large-area sky-blue perovskite LEDs.

On the basis of the work of preparing large-area, high-efficiency red perovskite LEDs by blade coating, Xiao Zhengguo's group adjusted the composition of perovskite and added additional halide amine additives to limit the growth and passivation of perovskite grains Defects, to achieve sky blue light emission. At the same time, dimethyl sulfoxide was partially replaced with formamide, resulting in a more volatile and supersaturated perovskite precursor solution. During the blade coating process, the perovskite nuclei will be directly precipitated from the inside of the supersaturated solution, which can effectively increase the density of the nuclei and shorten the process of nucleation growth, thereby producing uniform, dense, and small-grained perovskite.

The experimental results show that the sky blue perovskite LED prepared by the blade coating method has an area of ??up to 28 square centimeters, an external quantum efficiency of 10.3%, and excellent luminous uniformity and brightness.