By combining silver with a smidge of aluminum, researchers found a way to produce exceptionally thin, smooth layers of silver that are resistant to tarnishing. Then, they applied an anti-reflective coating to make one thin metal layer up to 92.4 percent transparent.
Screens require transparent electrodes to control which pixels are lit up, but touchscreens particularly depend on them. A modern touch screen, made of a transparent conductive layer covered with a nonconductive layer, senses electrical changes where a conductive object like a finger is pressed against the screen.
By adding about 6% aluminum, the researchers coaxed the metal into a film of less than half that thickness—seven nanometers. When it was exposed to air, the layer didn't immediately tarnish as pure silver films do. And, after several months, the film retained its conductive properties and transparency. It remained firmly attached, too, whereas pure silver can be removed off glass with Scotch tape.