Current Applied Physics, Vol.5, No.1, 71-74, 2005
Effect of dye dopants in poly(methylphenyl silane) light-emitting devices
To investigate the inter-molecular energy transfer between polysilane and dye dopants, poly(methylphenylsilane)(PMPS) was used as a host material and perylene as the blue dopant. The structure of the devices is indium-tin oxide (ITO)/PEDOT:PSS(30 nm)/ PMPS:perylene(dye dopant 0.1-1.0 mol%)(60 nm)/Alq(3)(20 nm)/LiF(0.5 nm)/AI(100 nm). Poly(3,4-ethylenedioxythiophene) (PEDOT): poly(4-styrenesulfonate) (PSS) is used as a buffer layer, tris(S-hydroxyquinoline)aluminum (Alq(3)) as hole transporting layer, LiF as hole injection layer. The device shows a luminance 810 cd/m(2) at current density of 28 mA/cm(2), luminous efficiency of 0.14 Im/W. The external quantum efficiency (EQE) is about 0.5% and EQE increased up to 0.52% by doping with single wall carbon nanotubes (SWNT) into the emissive layer. We found an efficient inter-molecular energy transfer from polysilane to dye dopants. Furthermore, using the polysilane and energy-matched dye dopants enable to fabricate the electroluminescence devices through wet processes. (C) 2004 Published by Elsevier B.V.