白光LED用YAG黄色荧光粉实用中发射光谱的测量方法

提出了一种YAG荧光粉在实用蓝光激发下发射光谱测量的新方法。通过采用高斯函数和费米函数拟合及模拟退火优化技术，得到了混合发光光谱的数学拟合函数，从而分离出荧光粉的发射光谱，进一步表征其发光性能。实验样品的测量结果表明，与简单的截切分离方法比较，具有不可忽略的光度量和色度量差异。量子效率、发光效率和能量效率等光度量的差异均高于1%，相关色温相差达几十K，色品坐标、主波长和色纯度等色品指标也产生差异，但半峰带宽变化不大，荧光发光的峰值波长则基本不受影响。实验结果表明，所建立方法能够提高实用条件下YAG黄色荧光粉发射光谱的测量准确性。

A Method for Measuring Emission Spectrum of YAG Phosphor Used in LED White Light under Practical Conditions

A new method for measuring the emission spectra of the YAG phosphor under blue light excitation was proposed. Utilizing the Gaussian function and Fermi function fitting and simulated annealing optimization techniques, mathematical fitting functions for matching mixed emission spectrum were obtained. And so, the emission spectrum of the YAG phosphor was separated, further its luminescence properties can be characterized. Our experiment results proved that its characteristic parameters present non-negligible differences. The optical metric differences such as those in quantum efficiency, light emitting efficiency and energy efficiency are higher than 1%. The difference in CCT (correlated color temperature) is up to tens of K, and chromaticity indicators also produce differences in chromaticity coordinates, dominant wavelength and color purity. But little change is there in the half-peak bandwidth, and peak wavelength is basically unaffected. All these show that the established method can improve the measurement accuracy of YAG yellow phosphor emission spectrum under practical conditions.