摘要
目前,高效窄带荧光粉的研发对于白光发光二极管(WLED)向高性能液晶显示器背光源的应用至关重要.本工作采用高温固相法制备了一种高效窄带蓝色荧光粉Ba_(3)Y_(2)B_(6)O_(15):Bi^(3+),并对其结构和性能进行了表征和计算.计算表明,Ba_(3)Y_(2)B_(6)O_(15)的带隙较宽,为4.67 eV,宽的带隙为高效率荧光粉提供了保障. Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)(0.5%为摩尔分数)的发射光谱峰值在409nm,半峰宽仅为2168cm^(-1)(36.2nm),属于窄带蓝光发射.Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)的内量子效率高达93.8%,色纯度也高达98.9%,其热稳定性能也较好,在150℃时的发光强度是室温发光强度的73.9%,且几乎没有色漂移.当Y被Sc部分取代时, Ba_(3)Sc_(x)Y_(2-x)B_(6)O_(15):Bi^(3+)(0≤x≤1.6)的发射光谱随着x的增大而发生红移.最终,将蓝色荧光粉Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)与商品化的红绿两种荧光粉混合均匀后涂在365 nm的芯片上制成WLED,在20 mA的电流驱动下,得到的WLED相关色温为5679 K,色域可达95.3%NTSC((美国)国家电视标准委员会).
At present,the development of efficient(high quantum efficiency and high thermal stability)narrow-band emitting phosphors is a crucial problem in the application of white light emitting diodes(WLED)for high-performance liquid crystal display(LCD)backlights.In this work,an efficient narrow-band blue emitting phosphor Ba_(3)Y_(2)B_(6)O_(15):Bi^(3+)was prepared by high temperature solid state method,and its structure and properties were characterized and calculated.By using the density functional theory(DFT),Ba_(3)Y_(2)B_(6)O_(15) is calculated to be a direct band gap material with a high band gap value of 4.67 eV,which is a necessary condition for achieving high quantum efficiency phosphors.The experiment results show that Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)has a narrow-band blue-emitting spectrum with a full width at half maximum(FWHM)of 2168 cm^(-1)(36.2 nm)at 409 nm,which is owing to the ^(3)P_(1)→^(1)S_(0) transition of Bi^(3+)ions.The emission spectra of Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)can be split into two peaks at 406 and 422 nm,respectively,because there are two kinds of Y ions(Y1 and Y2)in the crystal cell of Ba_(3)Y_(2)B_(6)O_(15).Under the 365 nm UV radiation,the Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)exhibits high internal quantum efficiency(IQE=93.8%),and ultra-high color purity(98.9%).The high quantum efficiency and narrow-band emission spectrum are mainly due to the compact and highly symmetric crystal structure of Ba_(3)Y_(2)B_(6)O_(15) matrix.The photoluminescence(PL)intensity of Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)remains 73.9% of the initial intensity at 150℃,and there is almost no color drift.The thermal quenching activation energy(Ea)of Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)was calculated to be 0.290 eV by the Arrhenius Equation,which indicates that Ba_(3)Y_(2)B_(6)O_(15):0.5%Bi^(3+)has high thermal stability.When Y3+is partially substituted by Sc^(3+),the emission spectrum of Ba_(3)Sc_(x)Y_(2-x)B_(6)O_(15):Bi^(3+)(0≤x≤1.6)is redshifted with the increase of x.Finally,the blue phosphor Ba_(3)Y_(2)
作者
梁攀
张宏淑
黄宏升
李飒英
张笑恬
王英
李连庆
刘志宏
Liang Pan;Zhang Hongshu;Huang Hongsheng;Li Saying;Zhang Xiaotian;Wang Ying;Li Lianqing;Liu Zhihong(School of Chemistry and Chemical Engineering,Shaanxi Xueqian Normal University,Xi’an 710100,China;School of Chemistry and Chemical Engineering,Shaanxi Normal University,Xi’an 710062,China;School of Chemical Engineering,Guizhou Institute of Technology,Guiyang 550003,China)
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2023年第4期371-380,共10页
Acta Chimica Sinica
基金
国家自然科学基金(Nos.22003035,21963006)
陕西省教育厅项目(No.21JK0587)资助。
