Eur. Phys. J. AP 4, 45-51 (1998)
https://doi.org/10.1051/epjap:1998242

Ion beam assisted deposition of organic light emitting devices: Enhanced optoelectronic properties

UMOP, Faculté des Sciences, 123 avenue Albert Thomas, 87060 Limoges Cedex, France

Corresponding author: amoliton@unilim.fr

Received: 19 February 1998
Revised: 29 April 1998
Accepted: 15 July 1998
Published online: 15 October 1998

Abstract

We present optoelectronic characteristics of organic light-emitting devices realized by Ion Beam Assisted Deposition (IBAD) of Alq3 (8-hydroxyquinoline aluminum) layer between an ITO anode and a Ca/Al cathode. The ion type is Iodine ion and the study against the ion beam energy (contained between 50 eV and 150 eV) indicates an optimization of the optoelectronic properties (internal quantum efficiency and luminance) at 100 eV while the optimized localization of the assisted layer is the area 25–50 nm. The characteristics log (J) = f (log [V]) indicates that the injection process takes place by trapped-charge-limited current and an estimation of the trap density N_t leads to N_t ≈ 10 ¹⁴ cm⁻³; the enhanced optoelectronic properties of devices obtained by IBAD are attributed to the limitation of quenching sites in the recombination area and also to charge carrier confinement at the interface assisted layer and virgin (non-assisted) layer.