Molecularly Doped Polymers as a Hole Transport Layer in Organic Electroluminescent Devices

Electroluminescent devices were fabricated using polycarbonate or poly(methyl methacrylate) molecularly doped with triphenyldiamine derivative as the hole transport layer and tris(8-quinolinolato)aluminum(III) complex (Alq) as the emitting layer, respectively. A cell structure of glass substrate/indium-tin-oxide/doped polymer/Alq/Mg:Ag was employed. Hole injection from the electrode through the doped polymer layer and concomitant efficient electroluminescence from the Alq layer were observed. Bright green emission with a luminance of 7700 cd/m2 was observed at a drive voltage of 14 V from the cell with the doped polycarbonate layer.