Asymmetry is key to creating more stable blue perovskite LEDs

Researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) have developed blue LEDs based on a material called metal halide perovskite, that, for the first time, uses asymmetrical bridges to hold the layers of perovskite together, creating a more stable structure.

The study, published recently in the Journal of the American Chemical Society, could bring perovskite LEDs one step closer to commercialization.

Aside from efficiency levels, perovskite LEDs also have numerous advantages over current LED technologies on the market, as they have the potential to produce brighter, purer colors at a fraction of the production cost.

However, the stability of perovskite LEDs remains a huge barrier, with the operational lifetime of even the most stable LEDs lasting only a few hundred hours. Blue LEDs, in particular, have lagged behind red and green-colored LEDs, with a lifetime of less than 2 hours and around half the level of efficiency.

But without blue LEDs, practical applications using perovskites in color displays or as light sources are limited, as red, green and blue light need to be mixed to produce the full array of colors, including white, explained Professor Yabing Qi, senior author of the paper and head of the OIST Energy Materials and Surface Sciences Unit.