ABSTRACT
We have investigated the effect of plasma-induced damages on the electron transport layers in organic light-emitting devices. Tris(8-hydroxyquinolinato) aluminum, tris(2,4,6-trimethyl-3-(pyridine-3yl)phenyl) borane, and 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ) layers were used for studying plasma-induced degradation of electron transport materials. The thicknesses, photoluminescence spectra and the current-voltage curves of organic electron transport materials were measured after exposing to Ar plasma. The high-energy species in plasma induce the sputtering of organic layers, quenching of emission sites, and the creation of defect sites in organic layers. The plasma-induced damage was strongly dependent on the glass transition temperature, exhibiting the most serious degradation in the TAZ with low glass transition temperature.
Funding
This work was supported by the Soonchunhyang University Research Fund and the IT R&D program of MOTIE/KEIT (100410642 development of fundamental technology for light extraction of OLED).