氮化镓基LED结温测量方法研究

分别研究了脉冲电流法、微小电流法和光学成像法测量氮化镓基LED结温的基本原理,并对比了不同方法的结果可靠性。结果表明:在大脉冲电流下,串联电阻效应不可忽略,脉冲电流法得到的平均结温偏低；微小电流法能够减小加热电流和测试电流的切换时间和串联电阻效应,提高测量准确性；光学成像法基于发光强度与结温的依赖关系,能够获得器件温度的空间分布,有助于制备高性能的LED。

Study on Junction Temperature Measurement of GaN-Based LED

The basic principles of various test techniques for measuring the junction temperature of GaN-based light-emitting diodes (LED) were studied, including the pulse current method, the small current method and the optical imaging method. The reliabilities of different methods were compared. The results show that, at a large pulse current, the series resistance effect cannot be ignored, which leads to a rather lower average junction temperature. The small current method is able to reduce both the switching time between the heating current and the test current and the series resistance effect, which improves the measurement accuracy. The optical imaging method is based on the relationship between the light intensity and the junction temperature, which allows to obtain the spatial distribution of the temperature of devices, and could be helpful for fabricating high-quality LED.