Flexible light-emitting three-terminal device with color-controlled emission

A new architecture for flexible light-emitting devices with color-controlled emission is described. The various layers in these novel three-terminal devices are fabricated by casting soluble conjugated polymers from solution. The light-emitting three-terminal device (LET) can be described as comprising two polymer light-emitting diodes (LEDs) connected back-to-back with an internal common electrode. By controlling the bias voltages between the common buried electrode and the two outer electrodes, the LET can be turned on/off, and the emission color can be switched and modulated. Thus, the LET architecture provides a route to flexible displays that can be fabricated by printing technology with pixels that are color-switchable and color-tunable.