Heat transfer property of thin-film encapsulation for OLEDs

We investigate the heat transfer property of thin-film encapsulation (TFE) for organic light-emitting diodes (OLEDs). It is demonstrated that the TFE combined with a flexible heat sink shows better thermal performance, compared with the epoxy-filled glass encapsulation and the conventional glass encapsulation. By way of experiments and simulations, we verify that the multi-heterojunction configuration and the low thermal conductivity of the polymer layer in the TFE film have no impact on the thermal performance. Furthermore, we find through simulations that a significant temperature gradient appears inside the TFE layers only when the thermal conductivity of the polymer is lower than 1 x 10 (3) W/m K. This enables us to perform design optimization of the TFE configuration with relaxed heat dissipation. (C) 2010 Elsevier B.V. All rights reserved.