Stretchable OLED displays can double in size without losing brightness

Researchers from Seoul National University and Drexel University have achieved a breakthrough in display technology by creating stretchable OLED panels.

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What could be the holy grail of modern day display technology was achieved through a class of materials called MXenes. Traditional OLEDs work by layering conductive and organic materials that emit light when electrical charges meet. Engineers have been using indium tin oxide (ITO) as the transparent electrode as it conducts electricity well while enabling light to pass through it. The limitation is that ITO is brittle and cracks when under pressure, resulting in brightness loss. This means its unsuitable for a display that needs to stretch.

MXenes are ultrathin, highly conductive materials that are made of layered carbides and nitrides. MXenes are also capable of bending and stretching without breaking as their layered structure enables sheets to slide past one another instead of fracturing under the pressure. Researchers used MXenes as a replacement for ITO, enabling the display to become both stretchable and produce stable levels of brightness.

In fact, the MXenes-powered display reached an external quantum efficiency of 17%, which is a marker for how effective electrical energy is converted into light. Researchers stated this is a record for stretchable OLED displays.

"We were able to double the size, achieving 200 percent stretching without losing performance," said Yury Gogotsi, a materials scientist at Drexel University in Philadelphia, a co-lead on the discovery

What does this mean? Stretchable displays are one step closer to no longer being purely science fiction. New technologies may emerge from stretchable OLEDs, such as skin-mounted electronics, soft robotics, and flexible consumer devices.

"We started with computers occupying the room, then moved to our desktops, then to laptops, then we got smartphones and iPads, but still we carry stuff with us. Flexible displays can be on the sleeve of your jacket. They can be rolled into a tube or folded and put in your pocket. They can be everywhere," said Gogotsi