双钙钛矿Cs_(2)NaInF_(6):Mn^(4+)荧光材料的发光性质与LED应用研究

On luminescence properties of Cs_(2)NaInF_(6):Mn^(4+)double-perovskite red-emitting phosphor for LED applications

高效红光材料开发是制备温暖照明光源的关键一环.利用氟化物较低的声子能量和较弱的电子声子耦合效应,设计了一种Mn^(4+)激活的双钙钛矿Cs_(2)NaInF_(6)红光材料,对材料的晶格结构、元素组成、表面形貌、能带结构、格位占据情况、激发和发射光谱、量子效率和荧光寿命进行了系统的表征和研究.结果表明,材料在紫外和蓝光区的激发带较宽,在红光区的发射峰半峰宽较窄,且掺杂粒子数分数为0.27%的样品具有最强的荧光发射和最高的量子效率(69%),其荧光寿命为5.65 ms.基于“红−黄−蓝”三色组合的白光LED器件具有较高的显色指数(93.0)和较低的色温(2914 K),表明了其在暖白光LED器件上的潜在应用价值.

The exploration of highly efficient red-emitting phosphor is crucial for the preparation of warm lighting sources.Based on the low phonon energy and weak electron phonon coupling effect of fluoride,we designed and conducted a novel Mn^(4+)-activated Cs_(2)NaInF_(6) double-perovskite red-emitting phosphor in this research.The lattice and electronic structures,elemental composition,morphology,band structure,photoluminescence excitation and photoluminescence spectra,quantum efficiency and lifetime were investigated systematically.The results show that the optimal doping amount of Mn^(4+)in Cs_(2)NaInF_(6) is 0.27%,which presents broadband excitation and narrowband emissions in blue and red regions,respectively.The corresponding quantum efficiency and lifetime are of 69%and 5.65 ms respectively.Warm WLED device based on the"red-yellow-blue"combination system exhibits a high color rendering index of 93.0 and a low correlated color temperature of 2914 K,evidently indicating the obtained red-emitting phosphor is potentially applicable for warm white light illumination.