EFFECT OF DIPOLAR DEFECTS ON TRAPPING OF CHARGE-CARRIERS IN HIGHLY ANISOTROPIC POLYDIACETYLENE CRYSTALS

Depths and cross sections of traps for charge carriers, associated wit h the presence of dipolar defects in highly anisotropic (quasi-one-dim ensional) molecular solids were calculated employing a simple electros tatic model. The parameters of trapping centres are linearly dependent on the magnitude of the dipole moment. The field dependence of the cr oss sections and the depths of the dipolar traps, particularly pronoun ced at elevated fields, may account for high-field effects, observed i n transport experiments performed on single-crystalline polydiacetylen es.