Bright blue electroluminescence from poly(N-vinylcarbazole)

Electroluminescent devices were fabricated using poly(N-vinylcarbazole) (PVK) as a hole-transporting emitter layer and a double layer of 1,2,4-triazole derivative (TAZ) and tris(8-quinolinolato)aluminum(III) complex (Alq) as an electron transport layer. A cell structure of glass substrate/indium-tin-oxide/PVK/TAZ/Alq/Mg:Ag was employed. In this cell structure, carrier injection from the electrodes to the PVK layer and concomitant electroluminescence from PVK were observed. Blue emission peaking at 410 nm and a luminance of 700 cd/m2 were achieved at a drive voltage of 14 V.