Organic Light-Emitting Diodes with Magnesium Doped CuPc as an Efficient Electron Injection Layer

Bright organic electroluminescent devices are developed using a metal-doped organic layer intervening between the cathode and the emitting layer. The typical device structure is a glass substrate/indium-tin oxide (ITO)/copper phthalocyanine(CuPc)/N,N-bis-(1-naphthl)-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB)/Tris(8-quinolinolato) alu-minum(Alq3)/Mg-doped CuPc/Ag. At a driving voltage of 11 V, the device with a layer of Mg-doped CuPc (1:2 in weight) shows a brightness of 4312 cd/m2 and a current efficiency of 2.52 cd/A, while the reference device exhibits 514 cd/m2 and 1.25 cd/A.