【作者】 王力； 范冰丰； 冼钰伦； 王钢；

【Author】 Wang Li,Fan Bingfeng,Xian Yulun,Wang Gang (State Key Laboratory of Optoelectronic Materials and Technology, Sun Yat-Sen University,Guangzhou 510275,China)

【机构】 中山大学光电材料与技术国家重点实验室；

【摘要】 GaN基白光LED以其效率高、响应快及尺寸小等优点,有望成为下一代的照明光源。但是要想取代传统照明光源,LED的光输出仍然是一个局限。提高光输出最直接的办法就是提高工作电流密度,但是光输出随着电流密度的增加会出现饱和,而且会带来严重的热问题。为了解决这些问题,考虑了在照明领域用脉冲电流来驱动大功率LED的可能,比较了直流和脉冲两种情况下LED的性能表现,这些性能包括电学、光学和热学等各方面;详细讨论了脉冲信号的参数对光输出的影响。研究结果表明对于LED在照明方面的应用而言,在相同的电注入功率下,直流情况下LED的光通量要比脉冲情况下的光通量高。更多还原

【Abstract】 Gallium nitride based LEDs are demonstrating for the next generation of light sources because of its high efficiency,fast response and small dimensions in this kind of devices.However, the lumen output of GaN-based LEDs still present limitations if they are hoped to replace the traditional sources.Increasing LED current density is the natural way of getting more light power from one LED.However,dependence of LED output efficiency on current density is maximum. And this method will bring a sequence thermal problems.The possibility of LEDs being used as light source driven by pulsed current is demonstrated.So an experimental analysis of LEDs performance under DC and pulsed current bias was presented.The analysis was carried out by means of current-voltage,integrated optical power and temperature.Comparison between DC and pulsed stress carried out using the same average power level and different duty cycle values show that the use of DC can produce more lumen power with respect to pulsed bias.更多还原