DOPING EFFECT ON ORGANIC SEMICONDUCTIVE THIN-FILM BY PLASMA POLYMERIZATION OF 3,4,9,10-PERYLENETETRACARBOXYLIC DIANHYDRIDE

Change in electronic properties of the doped material by plasma polymerization of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) have been examined. It has been shown that electrical conductivity of the iodine-doped sample decreases by five orders of magnitude. This counter-intuitive doping effect has been analyzed by infrared (IR) and electron spin resonance (ESR) measurements. It is concluded that the iodine doping causes a serious structural change rather going back to that of the evaporated PTCDA film. On the other hand, an n-type doping causes almost no appreciable change in the same material.