In 1907, a 25-year-old Marconi radio researcher named H. J. Round applied a voltage to a crystal of Carborundum and inadvertently discovered the light-emitting diode. That first feeble glow has, more than 100 years later, become an $8-billion-a-year industry, producing LEDs of nearly every color and intensity, providing illumination for everything from searchlights to night-lights. But though they’re more efficient than incandescent bulbs, and longer lasting than fluorescents, their relatively high manufacturing costs have kept LEDs out of living-room lamps until recently. And their tenure there may be short-lived, thanks to the development of organic light-emitting diodes (OLEDs).
Unlike crystalline LEDs, an OLED’s light comes from a thin organic film sandwiched between two electrodes. This film can be sprayed onto nearly anything, even flexible surfaces like paper, plastic, or cloth, with nothing more elaborate than ink-jet printer technology. With the addition of some cheap microprocessors, a single OLED surface can at different times serve as a light source, a cinema display, a computer monitor—even a mirror!
Because they can be embedded into objects, OLEDs will force us to reevaluate our thinking about interior lighting. For centuries, natural light has come into our homes through large rectangular windows and doors, while artificial light has usually come from point sources like candles, gas flames, and incandescent bulbs. How will we change our conception of the way a room should be lit when the entire ceiling—or the walls, or the carpet, or the couch—can glow?