Heat exchange of organic light emitting devices

Heat exchange characteristic of organic light emitting devices (OLED) is investigated by adopting simplified thermal resistance model and one-dimensional steady state equation of heat conduction. To improve the performance of OLED, new structure of OLED is designed and developed. The inner temperature distribution of OLED is presented and the formula is proposed by considering the relationships of temperature rising with input power, heat exchange coefficients, thicknesses and proportions of substrate and every organic layer film. The research reveals that the inner temperature distribution in OLED is mainly influenced by heat exchange performances of organic layers and substrate in the OLED, and the highest temperature is gained in the light layer AlQ3 of OLED with 29 K higher than the environment temperature when the environment temperature is 300 K and the power density is 1. 167×104 W/m2. So it is benefit to select the organic materials with better thermophysical properties and keep perfect connection between the organic layer and electrode. The experiments verify the validity of the model with different thickness of Al-cathode under the same input power.