Correlation between the Indium Tin Oxide morphology and the performances of polymer light-emitting diodes

G. Wantz (1, 2) , L. Hirsch (2, 3) , N. Huby (1, 2, 3) , L. Vignau (1, 2) , Jean-François Silvain (4) , A. S. Barriére (2, 3) , J. P. Parneix (1, 2)

1 LPIOM - Laboratoire de physique des interactions ondes matières
2 IMS - Laboratoire de l'intégration, du matériau au système
3 IXL - Laboratoire d'études de l'intégration des composants et systèmes électroniques
4 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

This paper reports on performance enhancement of polymer light-emitting diodes (PLEDs) based on poly(2,5-bis(3′,7′-dimethyl-octyloxy)1,4-phenylene-vinylene) (BDMO-PPV) after Indium Tin Oxide (ITO) pre-treatment. Diluted aqua regia surface treatments of ITO substrates were investigated before PLEDs manufacturing. The correlation between ITO surface morphology and the properties of devices were discussed. The residual roughness, the global ITO thickness and developed anodic active area were found extremely dependent on treatment time. The performances of the ITO/BDMO-PPV/Ca/Al diodes were improved. With long treatments, the roughness was dramatically increased and poor PLEDs performances were achieved. The incorporation of a conducting polymer layer, poly(3,4-ethylene dioxythiophene) doped with polystyrene sulfonate, between the ITO layer and the emissive polymer, was also studied. With this buffer layer, no effect of the acidic treatment was observed on luminance–voltage characteristics and low turn-on voltage devices were made.

Mots clés: Polymer light emitting diode; Indium tin oxide; Atomic force microscopy; Rutherford backscattering spectroscopy

Domaines: Matériaux

G. Wantz, L. Hirsch, N. Huby, L. Vignau, Jean-François Silvain, et al.. Correlation between the Indium Tin Oxide morphology and the performances of polymer light-emitting diodes. Thin Solid Films, 2005, 485 (1-2), pp.247-251. ⟨10.1016/j.tsf.2005.03.022⟩. ⟨hal-00015487⟩