White organic light-emitting diodes via mixing exciplex and electroplex emissions

The authors report the fabrication of white organic light-emitting devices and discuss their electroluminescence (EL) properties. The device structure is ITO/TPD (50 nm)/BCP (8 nm)/Rubrene (0.5 nm)/BCP (10 nm)/Alq3 (20 nm)/LiF (1 nm)/Al. In the EL spectra of this device, two new emissions peaking at 590 and 630 nm have been observed. These two emissions should be attributed to triplet exciplex and electroplex occurring at TPD/BCP interface. White emission was obtained based on this device under 12 V driving voltage, the Commission Internationale de l’Eclairage (CIE) coordinates arrives to (0.31, 0.33).