Bipolar injection as a cause of electrical switching phenomena in thin organic films

An investigation of electrical conductance switching phenomena in thin organic films has been carried out. For thin films of p-quaterphenyl and tetracene grown in high vacuum the electrical conductance, dynamic capacitance and temperature patterns corresponding to the distribution of electrical current density have been measured. The measurements were carried out in vacuum as well as in humid air. It is suggested that previously reported switching phenomena are caused by field-induced bipolar injection of charge carriers.