White organic light-emitting devices using 2,5,2′,5′-tetrakis(4′-biphenylenevinyl)-biphenyl as blue light-emitting layer

White organic light-emitting devices (OLEDs) have been fabricated using a trimeric phenylenvinylene derivative, 2,5,2′,5′-tetrakis(4′-biphenylenevinyl)-biphenyl (TBVB), as blue light-emitting layer. The structure of devices is simple, in which tris(8-hydroxyquinoline) aluminum (Alq), N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine, TBVB, and an ultrathin layer of 5,6,11,12-tetraphenylnaphthacene (rubrene), which is inserted between Alq and TBVB layers, are used as electron-transporting, hole-transporting, blue, and yellow light-emitting layers, respectively. A fairly pure white OLED with Commission Internationale De L’Eclairage coordinates of (0.33,0.34) at 4000 cd/m2 is realized when the thickness of TBVB is 10 nm and that of rubrene is 0.15 nm. The maximum luminance and efficiency of this device are 4025 cd/m2 and 3.2 cd/A, respectively.