ON MECHANISM OF CHARGE CARRIER GENERATION IN THIN LAYERS OF MOLECULAR ASSOCIATES

Measurements are made of the dependence of the electrical current on voltage and sample thickness for thin layer systems of some molecular associates (MA) with intermolecular hydrogen bonds. The results show that the MA under investigation may be divided into two groups with respect to the mechanism of charge carrier generation in high electrical field (ϵ = 104 to 106 V/cm). For the first group of MA, the ohmic region of C—V characteristics is followed by a non‐linear injection region of space charge limited current (SCLC) type with a quasi‐continuous exponential trap distribution. At higher electrical fields (ϵ > 105 V/cm) the injection region passes to the dominating bulk ionization region. For the second group of MA the bulk ionization region follows directly after the ohmic region. The main experimental criteria of both mechanisms are discussed. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim