The researchers use the same equipment that is employed to make electronics on glass screens for LCDs. They glue plastic on a piece of glass, make the thin-film transistors on the material, and then peel off the plastic. “We’ve only added two extra steps: gluing and peeling,” Colaneri says.
LCD electronics are processed at temperatures of above 300 °C, which can melt plastic. The FDC process works at a relatively low temperature of 180 °C. The process has required a lot of fine-tuning. The temperature is low enough that amorphous silicon transistors typically don’t perform well. “A lot of people have not been able to get good-quality amorphous silicon transistors at low temperatures,” says Mark Hartney, chief technical officer at the FlexTech Alliance, a display-industry consortium. “That’s really unique about what [FDC] have done.”
Yet at temperatures above 100 °C, “plastic tends to melt or stretch or wrinkle, so there’s distortion,” says Jennifer Colgrove, an analyst with the consulting firm DisplaySearch. “What’s significant here is that they can build amorphous silicon transistors on plastic with almost no distortion.”
Hartney says that this is a good starting point for manufacturing bendable OLED displays on a commercial scale. “Amorphous silicon is a mainstream tech for LCD manufacturing around the world today,” he says. “This opens the doors to being able to utilize any LCD fabrication facility. There has been billions of dollars of investment in LCD manufacturing capacity. You could go into any other LCD fab around the world and do the same process to get a flexible OLED product.”