采用红外热成像与瞬态热学测试技术,测试并对比分析了有机电致发光二极管(OLED)的光电热学特性。研究表明,OLED结温的升高会导致输入电压的降低。在输入电流为100mA时,整个面板上呈现非常明显的温度梯度,最高点与最低点温差可高达30℃。在相同的工作条件下,采用红外热像测试获得的峰值温度比采用瞬态热学测试获得的温度要高,且温度梯度会随输入电流的大小发生变化。结合红外热像与电学测试法固有特点的分析,指出两者的结合可以为OLED面板的热学设计与分析提供更具有指导意义的信息。
Organic light emitting diodes (OLEDs) have kept attracting many researchersr attention due to the distinct advantages and huge potential application prospect. Rapid developments in the electrical and optical performance of OLEDs have been obtained and the reliability problems have been solved to a cer- tain degree by advanced packaging approaches. However, the thermal management is still the key issue limiting the reliability of OLED considering the temperature sensitivity of organic materials and the low thermal conductivity of composing materials. In this paper, infrared (IR) thermal tracer and transient thermal tester are combined to evaluate the thermal performance of OLED. It is found that the increase of junction temperature can lead to the decrease of driving voltage. The temperature gradient up to more than 30 ℃ in the OLED panel is obtained at the input current of 100 mA. The peak temperature from IR imager test is higher than that obtained from electrical test method,and the thermal difference between them is not a constant when changing the input power. Based on the analysis of intrinsic properties of the two approaches, it is pointed out that the combination of them can offer more meaningful data for further device layout optimization.