IMPORTANCE OF POLY(N-VINYLCARBAZOLE) DOPANT TO POLY(3-OCTYLTHIOPHENE)ELECTROLUMINESCENCE

A new method is presented of enhancing the electroluminescence of shor t alkyl side chain paly(3-alkylthiophene) (P3AT) by adding poly(N-viny lcarbazole) (PVK) as a dopant in the emitting layer. The organic elect roluminescent (EL) diode with one layer of poly(3-octylthiophene) (P3O T) and P3OT doped with various amounts of PVK (P3OT/PVK) as the EL-emi tting layer sandwiched between indium/tin oxide and aluminum electrode s has been fabricated by spin-coating technique. The P3OT/PVK EL diode starts to emit red-orange light with an optimum molar ratio of P3OT t o PVK at 5 V. Evidence suggests that the PVK dopant plays an important role in the P3OT electroluminescence. Such a molar ratio of P3OT to P VK is found to exist and acting mechanism of the dopant is investigate d for enhancing the P3OT electroluminescence. (C) 1995 American Instit ute of Physics.