A new method for the determination of electronic mobility in organic materials associated with optoelectronic devices

摘要

It is proposed, by way of studies made using tris(8-hydroxyquinoline) aluminium (Alq3) in an ITO/Alq3/Al structure, that dielectric spectroscopy (represented by log epsilon ''=f[log omega]) and a determination of I(V) characteristics permit a good estimation of charge mobility (mu). The value of mu determined by this new method was found to be ca. 2x10(-6) cm(2) V-1 s(-1), without bias voltage. This method also allows a facile determination of field effects, and it was possible to demonstrate that mu followed a Poole-Frenkel law. In addition, mobilities determined via field effects alone generally led to overestimation of around one order of magnitude for an electric field of around 1 MV cm(-1).