基于反应动力学的GaN LED参数退化模型的研究

The investigation of LED degradation model based on the chemical kinetics

加速实验中,参数退化模型描述了参数的退化规律,参数退化规律对应于器件退化机理,而退化机理又对应于内部的物理化学反应.因此,本文基于反应动力学中物理化学反应的温度效应速率模型及反应量浓度随时间的变化规律,研究并建立了GaN LED参数退化模型.本模型尝试从物理机理上解释参数退化过程中的退化规律,包括单调上升或单调下降退化规律、先上升后下降或先下降后上升等非单调退化规律,解决了实验后拟合方法不能建立非单调退化模型的问题.然后对GaN LED进行加速实验,确定模型参数.同时对GaN LED的退化规律进行分解,并且量化了GaN LED两种退化规律的退化比例及时间常数.

The degradation of a device can be described by the degradation model in the accelerated tests. Because the degradation is closely related to the degradation mechanism, which reflects the intrinsic phySical or chemical reactions, the degradation model can be established based on the temperature effect on the reaction rate and the change of reaction volume concentration in the physi- cal/chemical reactions. Different degradation processes can be studied using the degradation model, including both the monotonic and nonmonotonic degradation processes. Moreover, the accelerated test is carried out for the GaN LED, figuring out the parameters for the degradation model, the ratio of different degradation processes, and the time constant.