有机电致发光器件的热学特性分析

采用COMSOL有限元分析软件的固体传热模块，对有机电致发光器件（OLED）的热学特性进行了仿真，发现器件温度随着输入功率成线性增大。在驱动电流为150 mAcm-2时，仿真结果表明，Alq3发光层的最高温度为82.994 3℃；玻璃基板下表面的最高温是77.392 6℃；器件阴极表面中心区域的最高温度为82.994 2℃，其平均温度为78.445℃。通过改变功能层热传导率、功能层厚度、对流换热系数、表面发射率等参数模拟其对OLED器件热学特性的影响，结果表明，当增加基板的热传导率时，OLED器件温度显著下降而且表面及内部温度梯度大幅减小；提高空气对流换热系数及基板的表面发射率，OLED的温度可以大幅减小。而其他参数则对其影响并不明显。

Analysis of thermal characteristics of organic light emitting device

The Joule heating inside organic light-emitting devices(OLEDs) is part of the device degradation factors. Therefore, it is very important to study the thermal characteristics of OLEDs for effective heat dissipation. So the thermal characteristics of OLED were simulated via the solid heat transfer module of COMSOL finite element analysis software. It is found that the device temperature increases linearly with the input power. At driving current of 150 mAcm-2, the highest temperature of the Alq3 emitting layer and bottom surface of the glass-substrate are 82.994 3℃ and 77.392 6℃, respectively, the highest temperature at the central region of the cathode surface is 82.994 2℃, and its average temperature is 78.445℃. Thermal analysis simulated results show the temperature distribution and thermal characteristics of an OLED can be affected by changing the thermal conductivity and thickness of functional layer, convection heat transfer coefficient, and surface emissivity. When increasing the substrate thermal conductivity, the temperature of the OLED is significantly reduced, and the surface and internal temperature gradients are greatly reduced; When improving the air convection heat transfer coefficient and the surface emissivity of the substrate, the temperature of the OLED can be greatly reduced. However, other parameters have no significant effect on improving thermal characteristics for the OLED.