2. Organic light-emitting diodes OLEDs

In 1960, Pope and colleagues first attempted to obtain an electroluminescence signal (i.e. light emission induced by an electric field) by applying a potential difference between two terminals sandwiching an anthracene crystal . Poor measured properties, in particular the need to apply a voltage of 500 V, discouraged further efforts in this field. Renewed interest arose in 1987, when Kodak demonstrated that an electroluminescence signal could be obtained at much lower voltages for a molecular film with a thickness of the order of a hundred nanometers