Influence of disorder on the electron transport properties in fluorinated copper-phthalocyanine thin films

Electron transport in polycrystalline thin films of fluorinated copper phthalocyanine is investigated by space charge limited current, photoconductivity, and field-effect transistor measurements in the temperature range from 200 to 300 K. In this region the conductivity follows the Meyer-Neldel rule. The Meyer-Neldel energy E-MN is connected to the characteristic energy of the exponential tail state distribution of localized states determined by voltage-dependent space charge limited current spectroscopy. Moreover, a correlation of the conductivity prefactor and E-MN is observed revealing a maximum energy barrier of 0.52 eV for the relaxation of trapped electrons. (C) 2001 American Institute of Physics.