基于荧光玻璃的高效LED白光技术

采用高温熔融法制备了一定质量比例的SiO_2-YAG∶Ce~(3+)片状荧光玻璃,厚度为0.2 mm,分析其XRD物相、光学和SEM微观结构、PL光谱。结果表明:荧光玻璃保留了晶相,荧光粉颗粒在玻璃基质中均匀分布,荧光玻璃和荧光粉的激发响应关系一致。在465 nm蓝光激发下,发射波长均在535 nm附近,表明荧光玻璃除含有玻璃相,还有荧光粉的物质结构特性。将不同波长蓝光芯片与不同荧光粉含量的荧光玻璃进行封装测试,结果表明:器件的流明效率可达到234.81 lm/W;色温和显色指数均随荧光粉含量增加而单调下降,呈现高色温和低显色指数;荧光粉质量分数从6%增加至15%时,不同波长激发下的色坐标x与y呈现大致相同的线性变化率。采用450 nm激光激发荧光玻璃,测试样品温度变化发现温升较缓,温降迅速,耐热性能优越。实验结果表明,将荧光玻璃用于LED白光照明封装,能实现流明效率和耐热性能的大幅提升,形成良好的白光输出。

High-efficiency Technology of LED White Light Based on Phosphor Glass

SiO2 glass powder and a certain mass proportion of YAG∶ Ce3 +phosphor powder were taken to prepare SiO2-YAG∶Ce3+ PG with melting method, and then the samples were prepared into 0. 2 mm thickness for XRD phase, structure of optical micrographs and SEM, and PL spectrum test analysis. The results show that the phase of phosphor is retained in PG and the phosphor particles are uniformly distributed in the glass matrix. Consistent excitation and response relationship of PG and phosphor is observed that the excitation wavelength is about 465 nm and the emission wavelength is about 535 nm. The structure characteristics of phosphor are retained in PG except the glass phase. The blue LED chips with different wavelengths were packaged with the PG samples. The test results indicate that the luminous efficiency can reach at 234. 81 lm/W, and the color temperature and CRI monotonically decrease with the increasing of phosphor content in PG, all of which are at a high level. Under different wavelength excitation, x and y in the chromaticity coordinates present roughly same linear rate of change when the mass fraction of phosphor in PG increases from 6% to 15%. In addition, the temperature of PG rose relative slowly and dropped sharply when the PG sam-ple was excited by 450 nm laser, indicating a nice property of heat resistance. The experiment re-sults show that the superior optical properties and heat resistance can be obtained by PG packaged LED, and excellent white light output can be formed.