Europhys. Lett.
Volume 72, Number 5, December 2005
Page(s) 754 - 759
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 04 November 2005
Europhys. Lett., 72 (5), pp. 754-759 (2005)
DOI: 10.1209/epl/i2005-10311-0

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

A. Moliton, W. Rammal and B. Lucas

Université de Limoges, Faculté des Sciences et Techniques, CNRS - FRE 2701 Laboratoire UMOP - 123 Av. Albert Thomas, 87060 Limoges, France

received 10 June 2005; accepted in final form 5 October 2005
published online 4 November 2005

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 $\log \varepsilon '' =f[\log \omega ]$) 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. $2\times
10^{-6}$ cm2 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 ${\rm
M}$V cm-1.

42.70.Jk - Polymers and organics.
72.80.Le - Polymers; organic compounds (including organic semiconductors).
85.60.Jb - Light-emitting devices.

© EDP Sciences 2005