摘要
白光LED具有广阔的应用前景与市场需求,而红色荧光粉对改善器件性能至关重要.本文采用高温固相法制备了一系列Li_(2)Gd_(4-x)Sm_(x)(MoO_(4))_(7)(x=0.01—0.13)荧光粉,利用X射线衍射、扫描电子显微镜、X射线光电子能谱和荧光光谱仪对样品进行了表征.在406 nm激发下,Li_(2)Gd_(4)(MoO_(4))_(7):Sm^(3+)荧光粉的发射峰分别位于563,598,645,706 nm处,这是由于Sm^(3+)的4f-4f跃迁引起的.当Sm^(3+)浓度为0.07时发光最强,浓度猝灭主要归因于电偶极-电偶极相互作用.随着Sm^(3+)浓度的增大,荧光寿命逐渐缩短.温度依赖性发射光谱研究发现,当温度为423 K时,Li_(2)Gd_(4)(MoO_(4))_(7):0.07Sm^(3+)的发射强度依然保持在298 K时的79%,显示了样品优良的热稳定性.CIE色度图确认了该荧光粉的发射位于橙红色区域.进一步利用最佳样品制作了白光LED,其CIE色坐标为(0.3788,0.3134),位于白光圈内.研究表明Li_(2)Gd_(4)(MoO_(4))_(7):Sm^(3+)荧光粉是一种很有前途的白光LED用橙红色荧光粉.
White LEDs have the broad application prospect and market demand,while the red phosphor can greatly affect the color temperature and color rendering index of the modulated white light.In this work,a series of Li_(2)Gd_(4–x)Sm_(x)(MoO_(4))_(7)(x=0.01–0.13)phosphors is prepared by the high-temperature solid phase method.The successful doping of Sm^(3+)into Li_(2)Gd_(4)(MoO_(4))_(7)is confirmed by X-ray diffractometry(XRD)and does not lead to any change in crystal structure.The samples are detected by scanning electron microscope(SEM)to have irregular blocky structures with particle size less than 20μm.The existence of Li,Gd,Mo,O and Sm elements in the phosphor is confirmed by energy dispersive X-ray spectroscopy(EDS).The observation of X-ray photoelectron spectroscopy(XPS)shows that the activators are successfully doped into materials.Under 406 nm excitation,the emission peaks of the samples are located at 563,598,645 and 706 nm respectively,which are caused by the 4f-4f transition of Sm^(3+),and the strongest emission peak comes from 4G5/2→6H9/2 transition.It is found that optimal concentration of Sm^(3+)is 0.07.With the increase of Sm^(3+)concentration,the fluorescence lifetime decreases gradually.The temperature-dependent emission of phosphor is also studied.The emission intensity at 473 K is still 79%of that at 298 K,indicating that the sample has excellent heat resistance.The CIE chromaticity diagram shows the luminescence of the prepared phosphor is located in the orange-red region and the color purity is high(99%).Moreover,a white LED is fabricated using the optical doped phosphor,which has CIE coordinates of(0.3788,0.3134)that are located in the circle of white light.Research shows that the Li_(2)Gd_(4)(MoO_(4))_(7):Sm^(3+)phosphor is a promising orange-red phosphor for white LEDs.
作者
禄靖雯
赵瑾
张永春
涂茹婷
刘馥妮
冷稚华
Lu Jing-Wen;Zhao Jin;Zhang Yong-Chun;Tu Ru-Ting;Liu Fu-Ni;Leng Zhi-Hua(College of Science,Xi’an University of Architecture and Technology,Xi’an 710055,China;School of Chemistry and Chemical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2024年第21期142-152,共11页
Acta Physica Sinica
基金
国家自然科学基金(批准号:11804265)
陕西省重点科技创新团队项目(批准号:2022TD-30)
陕西省自然科学基础研究计划(批准号:2024JC-YBMS-384)资助的课题。
