1. 中国科学院, 研究生院 北京,100049
2. 中国科学院长春光学精密机械与物理研究所, 激发态物理重点实验室,吉林 长春,130033
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WANG Jian, HUANG Xian, LIU Li, et al. Effect of Temperature and Current on LED Luminous Efficiency. [J]. Chinese Journal of Luminescence 29(2):358-362(2008)
Recently, people are seeking the lighting source which consumes less energy and has no pollution. Light Emitting Diode (LED) has the advantages over the traditional lamps in the future. The luminous efficiency of blue-light chip and the conversion efficiency of phosphors determine the luminous efficiency of white light LEDs.The thesis experimentally demonstrates luminous efficiency of large-area, high-power blue-light LEDs. We study the high power blue LED and discover the influence of temperature and current on luminous efficiency. When operation temperature increases from 327 K to 380 K,the light efficiency of LED decreases 20%.The temperature rising,the radiation at the potential well decreases, so as to decrease the luminous efficiency. When operation current increases from 50 mA to 350 mA, the luminous efficiency of LED decreases 35%.The current increasing,the more nonequilibrium electron diffuse out of the potential well,so as to decrease luminous efficiency. Enhancing the heat dissipation efficiency and increasing the width of potential well can improve the luminous efficiency. LED should be working under the limit temperature and the saturated current.LED can work at high current relatively when the thermal dissipation is good. The heating generation will decay the lighting performance. Therefore, the thermal dissipation controls the development of the LED and the goal of our investigation is to increase the efficiency of the thermal dissipation. A good packaging technology is the way to solve the heat dissipation problem. But it is a challenge to develop this technology in the limited space of LED.The purpose of heat dissipating technology for LED is to decrease the working temperature of LED's chip.It is necessary to reduce the thermal resistance of LED package.The efficiency and reliabi-lity of solid state lighting devices depends strongly on successful thermal management,because the junction temperature of the chip is the prime driver for effective operation.As the power density continues to increase,the integrity of the package electrical and thermal interconnects become extremely important.
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