大功率GaN基发光二极管等效串联电阻的功率耗散及其对发光效率的影响  

The power dissipation of equivalent series resistance and its influence on lumen efficiency of GaN based high power light-emitting diodes

作　　者：李炳乾[1] 刘玉华[1] 冯玉春[2] 

机构地区：[1]佛山科学技术学院光电子与物理学系,佛山528000 [2]深圳大学光电子学研究所广东省光电子器件与系统重点实验室光电子器件与系统教育部重点实验室,深圳518060

出　　处：《物理学报》2008年第1期477-481,共5页Acta Physica Sinica

基　　金：广东省自然科学基金(批准号:04011642);佛山市科技发展专项基金(批准号:04030021);教育部光电子器件与系统重点实验室开放基金资助的课题~~

摘　　要：由于自加热效应的存在,大功率GaN基发光二极管(LED)的芯片温度有可能高出环境温度很多,实验中,芯片温度超出环境高达147K.从实验测量的大功率LED电流电压特性曲线中,将p-n结和等效串联电阻上的电压降落分离出来,得到了大功率LED等效串联电阻随芯片温度的变化情况.在输入电功率自加热效应的影响下,大功率GaN基LED等效串联电阻呈现出剧烈的变化,其阻值由低输入功率时的1.2Ω降低到0.9Ω,然后再升高到1.9Ω,等效串联电阻的功率耗散在输入功率中所占的比例也随着输入功率的增加迅速增加,最高时接近50%,成为大功率输入时影响LED流明效率的主要因素.Because of the self-heating effect of InGaN based high power light-emitting diodes （LEDs）, the temperature of the LED chip is much higher than the case temperature （ Tc）. The maximum Tj in our experiment is 148K higher above the case temperature. The voltage drops on p-n junction and equivalent series resistance are extracted from the measured I-V curve, and then the values of equivalent series resistance at different forward power are obtained. Due to the self-heating effect, the values of equivalent series resistance show a very strong forward power-dependent characteristics, the maximum equivalent series resistance reported in this paper is about 1.9Ω at high forward power, being more than twice the minimum value. The power dissipation of equivalent series resistance is increased sharply when the forward power is increased, nearly half of the forward electrical power was dissipated on equivalent series resistance at high power, and it becomes the an important factor restraining the lumen efficiency of high power GaN based light emitting diodes.

关 键 词：自加热 等效串联电阻 发光二极管 流明效率 

分 类 号：TN312.8[电子电信—物理电子学]