LOW-TEMPERATURE CONDUCTIVITY OF IRRADIATED AMORPHOUS CONDUCTING CARBON

Conducting carbon films prepared by pyrolysis of perylene-3,4,9,10-tet racarboxylic dianhydride (PTCDA) were subjected to high energy ion irr adiation with I13+ ions (170 MeV). Different doses in the range 10(11) -10(13) were used. XRD observation (at room temperature) and electrica l conductivity measurements down to 6.3 K were carried out on These fi lms before and after irradiation. XRD shows that the structure remaine d amorphous as before. The temperature dependence of conductivity show ed an interesting change below about 20 K, suggesting an emergence of a mobility gap in the electronic structure. Copyright (C) 1996 Elsevie r Science Ltd