摘要
荧光粉的吸收散射特性、粒径分布及荧光粉涂层的形状对白光LED色温角空间分布具有直接影响。通过Mie散射理论对不同形状的荧光粉涂层进行了光学计算仿真,研究了荧光粉涂层形状对白光LED空间色温分布的影响规律,以及不同形状的荧光粉涂层效率,并从中找出色温均匀性最佳的荧光粉涂层形状。根据仿真结果,采用具有精确控制喷胶量和喷涂位置功能的高速喷胶技术对1mm2大功率芯片的荧光粉涂层的涂敷工艺进行实验制作,控制器件的平均色温在5 000K,获得荧光粉涂层形状对白光LED色温角空间分布影响的测量结果与计算仿真结果相吻合。通过该方法制作的荧光粉涂层使白光LED的最小色温差异达到537K,远优于目前一般采用的荧光粉涂敷技术。
The phosphor size,the absorbing and scattering character,and the shape of phosphor layer have direct influence on correlated color temperature（CCT） distribution in space.Based on the Mie theory and Monte-Carlo method,the CCT distributions of White LED with different shapes of phosphor layer are simulated.According to the simulation results,the influence of phosphor layer shapes on CCT uniformity and the efficiency differences are studied,and the best shape of phosphor layer is obtained.Besides,the phosphor layers on the chip of 1 mm2 are made at average CCT of 5 000 K by high-speed spraying machine,which can accurately control the phosphor solution quantity and spraying place.And the least CCT difference of 537 K in White LED is achieved,which is far less than that gotten with common phosphor coating technologies.
出处
《半导体光电》
CAS
CSCD
北大核心
2012年第5期651-656,671,共7页
Semiconductor Optoelectronics
基金
国家"863"计划项目(2008AA03A194)
深圳市科技研发资助项目(2009003)
