This Flexible, Transparent MXene OLED Display Scrubs Up Well — Even After Hours Under Water
Tested for 1,000 bend cycles and six hours submersion, this tough yet flexible display is bright enough for outdoor use.
Researchers from the Korea Advanced Institute of Science and Technology (KAIST), Gachon University, and Korea's National Nano Fab Center, have developed an organic light-emitting diode (OLED) display with a difference: the MXene-based device is transparent, flexible, washable, and can even work under water.
"This research will become the guideline for applying MXene in electrical devices, but we expect for it to also be applied in other fields that require flexible and transparent displays like automobiles, fashion, and functional clothing," claims project lead Kyung Cheol Choi, professor of electrical engineering, of the work. "And to widen the gap with China’s OLED technology, these new OLED convergence technologies must continue to be developed."
Choi's team isn't the first to build displays using MXenes, two-dimensional titanium carbide materials, for their electrodes — but what his team has created is the first to offer a high enough resolution to be useful as a functional display and with an air-gap-free encapsulation system which means water won't stop it working.
The red/green/blue (RGB) color OLED built by the team offers a peak brightness of over 1,300 candelas per meter squared (1,000cd/m²), good enough for outdoor use, while testing on the red variant showed it able to run for over 1,500 hours and withstand bending to a sub-1.5mm curvature for 1,000 cycles without damage. Its ability to withstand a little water, meanwhile, extended to operation following submersion in water for over six hours.
"To improve the reliability of MXene OLED, we focused on producing an adequate encapsulation structure and a suitable process design," explains study lead So Yeong Jeong, a PhD candidate at KAIST. "By producing a matrix-type MXene OLED and displaying simple letters and shapes, we have laid the foundations for MXene’s application in the field of transparent displays."
The team's work has been published in the journal ACS Nano under closed-access terms.