非等温耦合模型下大功率LED特性的研究

The Investigation of High Power LED by a Non-Isothermal Coupling Model

本文建立了发光二极管(LED)芯片的非等温多物理场耦合模型。结果表明,芯片内热源集中在多量子阱(MQWs)区域,且靠近p-GaN的第一个量子阱(QW)内的内热源强度最高;焦耳热和非辐射复合热贡献大,而汤姆逊热和帕尔帖热贡献小,可忽略。等温模型与非等温模型的对比表明,在大电流或低冷却能力条件下,芯片内部与芯片衬底温差显著,等温模型无法准确预测芯片性能,需采用非等温模型。

A non-isothermal multi-physics coupling model for light-emitting diode has been established. The results show that the heat source is concentrated within the multiple quantum well（MQWs） region,and exhibits the highest intensity in the quantum well（QW） nearly to the p-GaN layer;Joule heat and non-radiative recombination heat contribute to most of the heat source, but Thomson heat and Peltier heat contribution are so small thus can be ignored.Besides,the comparison between isothermal and non-isothermal models shows that under high current or low cooling capacity conditions,the temperature difference between epilayer and substrate is very large, under this circumstance,the isothermal model can not accurately predicts the chip performance,it indeed requires the non-isothermal model.