Electrical Conduction of Anthracene Crystal

Electrical conductivity and activation energy were measured in doped-anthracene crystals and a highly purified anthracene crystal in a temperature range from 370 K to 420 K. It was found that the conductivity was proportional to the concentration of impurity molecules. Main carrier generation process in the dark conduction was deduced to be an extrinsic bulk generation associated with impurity molecules. Other mechanisms such as intrinsic generation or carrier injection from electrodes were denied. The conductivity and the activation energy were respectively 1.63 eV and 1.4×10 -17 ohm -1 cm -1 at 400 K in the direction perpendicular to the ab-plane of the purified anthracene crystal. It has not been reported that the conductivity lower than the above value has ever been observed.