18.03.2022 • Newslighting

Prototype of a large-area sky-blue PeLED

This new approach represents an important step to the commercial application of PeLED lighting.

The research group led by Xiao Zhengguo from the University of Science and Techno­logy of China (USTC) of the Chinese Academy of Sciences prepared large-area and efficient sky-blue perovskite light-emitting diodes (PeLEDs) by blade-coating super­saturated perovskite solution. Metal halide PeLEDs can achieve high luminance at low voltage due to their high electrical conduc­tivity, making them ideal for the next generation of energy-saving lighting.

Prototype of an ultra large-area sky-blue PeLED. (Source: S. Chu et al.)
Prototype of an ultra large-area sky-blue PeLED. (Source: S. Chu et al.)

The external quantum efficiency (EQE) of red/infrared and green PeLEDs is high at present. Blue/sky-blue PeLEDs are essential for white lighting, while the EQE of blue light is relatively low. This is because the crystalli­zation process of blue/sky-blue perovs­kite film is difficult to control, which results in poor film quality. Till now, there are no reports on the formation of large-area blue/sky-blue PeLEDs. The researchers adjusted the composition of perovskite into CsPb(Br0.84Cl0.16)3 based on their previous robust perovskite blade-coating technique for red PeLEDs. They added addi­tional halide amine additives to limit the growth of perovskite grains and passi­vate the traps, to achieve the sky-blue emission.

Meanwhile, they partially replaced dimethyl sulfoxide (DMSO) with dimethyl­formamide (DMF) to obtain a more volatile and super­saturated perovskite precursor solution. Perovskite crystal nucleus will precipitate directly from inside of the super­saturated solution in the process of blade-coating, which can effec­tively increase the density of the nucleus and accelerate the process of nucleation, crystalli­zation, and film-forming, to prepare uniform perovskite films with small grains.

The EQE for blue/sky-blue PeLEDs, prepared by the blade-coating method, reached 10.3 %, and the lumines­cence uniformity and brightness in an area of 28 cm2 of the PeLEDs are both very good. This new approach represents an important step to the commer­cial appli­cation of PeLED lighting. (Source: USTC)

Reference: S. Chu et al.: Large-Area and Efficient Sky-Blue Perovskite Light-Emitting Diodes via Blade-Coating, Adv. Mat., online 28 February 2022; DOI: 10.1002/adma.202108939

Link: National Laboratory of the Physical Science at the Microscale, University of Science and Technology of China (USTC), Hefei, Anhui China

Digital Events

Digital Event Calendar 2025
live or on demand

Digital Event Calendar 2025

By participating in our free digital events, you can stay up to date in your field of expertise.

Award

AutomationsBest Award

AutomationsBest Award

The AutomationsBest Award is now entering its 3rd round. The award will be presented at SPS - Smart Production Solutions on 25 November 2025

most read

Photo
10.06.2025 • NewsMachine Vision

The winners of the inspect award 2025

This time, with two additional categories, “SMEs” and “Artificial Intelligence,” the selection was even larger than usual. But now they have been chosen: the machine vision products of the year 2025.