Improvement of quantum efficiency in polymer electroluminescence devices by inserting pmma langmuir-blodgett films

Quantum efficiency in a polymer electroluminescence device is significantly improved by inserting a thin insulating layer with the thickness of tunneling range. Four times higher quantum efficiency was obtained without the increase of the threshold voltage. Poly(methyl methacrylate) Langmuir-Blodgett films were used as the thin tunneling barrier. The enhancement may result from the improved balance between the electron and hole injection into the light emitting devices.