A team of scientists describes a new OLED display that can pack in 10,000 pixels per inch with room to scale. In comparison, today’s smartphone and VR displays are less than 1,000 pixels per inch. The new display was born from a breakthrough in solar cells, where the scientists used optical metasurfaces — these are surfaces with built-in nanoscale structures to control a material’s properties—to manipulate light. The same approach could be useful in organic light-emitting diode (OLED) displays too.
Currently, there are two ways to make an OLED display. For small screens like smartphones, the pixels are split into subpixels that emit red, green, or blue light. These are laid down by spraying dots of each material through a fine mesh. But the method has limitations both in how small the subpixels (and therefore pixels) can be and how large the display can go. If the mesh is too big, it has a tendency to sag.
As the pixels are no longer shaded by filters—and due to a curious property of the optical metasurface that allows light to build up and resonate, a bit like sound in a musical instrument—the OLED display color is very pure and achieves greater brightness with less power.