MoS2 Thin-Film Transistors Allow for Flexible OLED Displays — Simple Skin Screen

Yonsei University researchers have developed a MoS2 (molybdenum disulfide) transistor that can be used to make ultra-thin bendable OLED displays.

One of the great things about 2D semiconductors is that they are readily deformable and allow electrons to pass freely and quickly while traveling through them. Since they’re only one-atom thick, they are transparent as well, making them an ideal choice for bendable displays. The problem is, if manufacturers try to make those displays using MoS2 transistors that are needed to control the pixels, the resistance is hampered between the metal/MoS2 interface, which is a ‘no-go’ for the transfer of carriers at the dialectic surface. That’s science jargon for the material won’t bend and remain viable for electron flow.

To get around that issue, the researchers placed the molybdenum disulfide-based transistors between a pair of aluminum oxide layers, which they noticed that the interface between the two materials enhanced the flow of electrons, thereby overcoming the resistance encountered when bending the material. As an added bonus, the researchers found the MoS2 also provided a boost in charge carrier mobility and because of the smoothness of the material; there are no places for a charge to become trapped.

To demonstrate their breakthrough, the researchers created a 6 x 6-pixel array OLED display on a 7mm flexible substrate that can be affixed to the skin like a Band-Aid. The display is capable of showing numbers and letters like an old LCD calculator and can withstand bending to a radius of just 1mm repeatedly. The researchers are hoping to scale-up their technology to produce a smartwatch and/or smartphone-sized displays in the near future.