发光学报, 2019, 40 (4): 432, 网络出版: 2019-06-10
双钙钛矿结构BaLaLiTeO6∶Eu3+红色荧光粉的光谱与LED封装特性
Spectra and Packaging Performance of BaLaLiTeO6∶Eu3+ Red-emitting Phosphors for White LEDs
高温固相法 LED用红色荧光粉 发光 BaLaLiTeO6∶Eu3+ BaLaLiTeO6∶Eu3+ high-temperature solid-state reaction red-emitting phosphor for LED luminescence
摘要
采用高温固相法在1 100 ℃下合成出一系列不同掺杂浓度的BaLa1-xLiTeO6∶xEu3+ (x=0.1~1)红色荧光粉,并对其结构、形貌、光谱特性及LED光色电性能进行了系统研究。结果表明,在BaLaLiTeO6中Eu3+的最大和最佳掺杂浓度均为x=0.4,更大的掺杂量将导致杂相和浓度猝灭的产生。在465 nm光激发下,该浓度的样品发射光谱中5D0 →7F2与5D0 →7F2强度比值达到了7.31,色品坐标值为(0.665,0.334),色纯度为99.7%,荧光寿命为660.9 μs,绝对量子效率达到71.4%。在100 ℃时积分发光强度是室温时的84.5%,热激活能经计算为0.434 eV。基于该样品的红光LED灯珠能够发出明亮的红光。综上所述,该类荧光粉表现出良好的发光效率、色纯度及发光热稳定性,在白光LED中具有潜在的应用价值。
Abstract
A series of BaLa1-xLiTeO6∶xEu3+ (x=0.1-1) red-emitting phosphors were synthesized by high-temperature solid-state reaction at 1 100 ℃, and their structure, morphology, spectra and packaging performance were investigated systematically. The maximum doping content of Eu3+ was equal to the optimum one, i. e., x=0.4, beyond which impurities and concentration quenching were observed. The asymmetry ratio of I(5D0 →7F2)/I(5D0 →7F1) reached 7.31, resulting in high color purity of 99.7% with CIE 1931 chromaticity coordinates of (0.665, 0.334). The fluorescent lifetime and absolute quantum efficiency were measured to be 660.9 μs and 71.4%, respectively. The integrated emission intensity at 100 ℃ was as high as 84.5% of that at ambient temperature. The thermal activation energy was determined to be 0.434 eV. The prototypical LED based on it enabled to emit bright red light. In conclusion, the phosphor exhibits favorable luminous efficiency, color purity and thermal stability of luminescence, which have potential application in white LEDs.
平兆艳, 赵旺, 郑庆华, 周薇薇. 双钙钛矿结构BaLaLiTeO6∶Eu3+红色荧光粉的光谱与LED封装特性[J]. 发光学报, 2019, 40(4): 432. PING Zhao-yan, ZHAO Wang, ZHENG Qing-hua, ZHOU Wei-wei. Spectra and Packaging Performance of BaLaLiTeO6∶Eu3+ Red-emitting Phosphors for White LEDs[J]. Chinese Journal of Luminescence, 2019, 40(4): 432.