CONTROLLED DOPING OF PHTHALOCYANINE LAYERS BY COSUBLIMATION WITH ACCEPTOR MOLECULES - A SYSTEMATIC SEEBECK AND CONDUCTIVITY STUDY

We investigate the doping of vanadyl-phthalocyanine by a fluorinated f orm of tetracyano-quinodimethane as an example of controlled doping of thin organic dye films by cosublimation of matrix and dopant. The ele ctrical parameters of the films derived from conductivity and Seebeck measurements show that the results largely follow standard models used to describe the doping of crystalline semiconductors; e.g., a smooth shift of the Fermi level towards the valence states with increasing do ping is observed. Other effects, like the superlinear increase of cond uctivity with the molar doping ratio, need the inclusion of additional effects like percolation. (C) 1998 American Institute of Physics. [S0 003-6951(98)00448-3].