The encapsulation of an organic light-emitting diode using organic-inorganic hybrid materials and MgO

Abstract

The characteristics of organic-inorganic multi-barriers were investigated in this study. Polymerized cycloaliphatic epoxy hybrid materials (hybrimers), synthesized by a sol-gel method and MgO were used as an organic and inorganic material, respectively. We performed a Ca test at 30 degrees C and 90% R.H. A multi-barrier of 6 dyads on 100 mu m thick PET resulted in a water vapor transmission rate (WVTR) of 4.9 x 10(-5) g/m(2) day and optical transmittance of 81.8% in the visible region (350-850 nm). We suggested relatively simple passivation method with a solution process involving an organic material coupled with low temperature deposition of MgO using an electron beam evaporator. Due to the solution process of the organic layer, the OLEDs were passivated without dark spots or an additional protective layer. After driving of 740 h with a constant current source under ambient conditions, a half-life time of 15,000 h was estimated by the stretched exponential decay (SED) model with an initial luminance value L(0) = 1000 cd/m(2). (C) 2011 Elsevier B.V. All rights reserved.