Electrical characterization of N- and P-doped hole and electron only organic devices.

We have fabricated a series of hole only devices with tungsten oxide (WO3) and molybdenum oxide (MoO3) n-doping materials in N,N'-diphenyl-N,N'-bis(1,1'-biphenyl)-4,4'-diamine (NPB) hole transport layer, and electron only devices with CsF and Cs2CO3 p-doping materials in 4,7-diphenyl-1,10-phenanthroline (Bphen) electron transport layer. Current-voltage characteristics and conductivity of these devices are investigated. The optimal conditions for ohmic injection and low resistance properties, and process margins of each dopant are reported in this paper.