A thirteen-year-long mystery that has involved a long series of researchers has finally been solved. A new article presents a diode in printed electronics that works in the GHz band, which opens up a new opportunity to send signals from a mobile phone to, for example, printed electronic labels. Energy from the radio signal is collected and used to switch the label's display. The diode being printed means that it is both cheap and simple to manufacture. Researchers have long known that the diode works, but not how and why.

Source: Mystery of the printed diode solved