研究了Sr2-xBaxSiO4∶Eu2+ 荧光材料作为白光LED发光体的可行性和应用特性。采用高温固相法制备了Sr2-xBaxSiO4∶Eu2+ 材料系列样品，对样品的成分配比、阴离子掺杂、合成温度和时间进行了系统实验，利用XRD、SEM、光谱测试及封装测试等手段对样品的组成、结构、形貌特征及应用性能进行了表征。研究表明Sr2-xBaxSiO4∶Eu2+ 荧光材料具有激发范围宽(300~500 nm)、发射范围宽(500~600 nm)的特点。通过控制碱土金属的比例可以精确控制材料的发射波长，在Ba掺杂范围0≤x<0.5内可以获得550~560 nm的发射，与YAG材料相比在光谱上增加了红色成分。通过引入恰当助熔成分进行阴离子掺杂，精确控制烧结工艺等手段极大提高了550~560 nm发射的发光强度和光转换效率。封装应用和测试证明，本研究优化制备的高性能Sr2-xBaxSiO4∶Eu2+ 荧光材料的光转换效率普遍可达到YAG材料的95％，在显色指数、色温和色纯度方面也优于或相当于YAG材料，并且具有较好的芯片适应性和较多的红色成分，是较为理想的应用于白光LED的荧光材料，特别适合于暖白光LED的制备。

In the last few years white light-emitting diodes (LEDs) have been the subject of increasing interest due to their advantages of low energy consumption, long lifetime, lack of pollutants and their potential applications in indicators, backlights, automobile headlights and general illumination. White light can be generated from LEDs through phosphor conversion method. The most commonly used LED conversion phosphor is YAG∶Ce3+. Although the phosphor is just the material opening the new stage of white light-emitting diodes, but the patent protection limits the broad application of this material. Furthermore, the characteristic of YAG itself also has limitation on the application aspect of LEDs. The excitation range of the material is too small and the maximum emission wavelength of the material can only reach to 540 nm. Lack of red component in the emission spectrum of the material may cause a relatively low color-rendering index when used in LEDs. Therefore, it is important to find some new LED phosphor, to accelerate the broad application of white-light LED in the field of illumination technology. In this paper feasibility and application performance of Sr2-xBaxSiO4∶Eu2+ (0≤x≤2.0) silicate material as a phosphor used for white-light LED was studied and discussed. A series of samples were prepared using solid-state reaction method under the reducing atmosphere. Systematic experiments in sample composition, anion doping, heating temperature and heating time as well as atmospheric condition were performed. The characteristics of the samples were measured using XRD, SEM, spectroscopic analysis and encapsulation test. Nearly single phased samples can be prepared in the barium substituting range of 0~2.0% and the crystal structure of the phase may slightly deformed as the content of barium increases. A series of Sr2-xBaxSiO4∶Eu2+ samples show a very broad excitation spectrum from 300 to 500 nm and a broad emission spectrum from 500 to 600 nm, which makes Sr2-xBaxSiO4∶Eu2+ rather suitable to be a conversion phosphor for white-light LEDs with different excitation wavelengths. It was also found that the maximum emission peak position of the samples shifts towards the short wavelength region as the content of barium increases and this can be explained from the aspect of co-valence and crystal field changes after substitution of barium. Maximum emission peak positions of 550~560 nm rather suitable for white-light LEDs can only be obtained in the barium substitution range of 0≤x＜0.5, and therefore detailed study on the material was performed in the barium substitution range of 0≤x＜0.5. Anion doping experiment indicated that light conversion efficiency of the Sr2-xBaxSiO4∶Eu2+ (0≤x＜0.5) samples can be obviously improved after co-doping of little amount (3%) of F- and Cl- ions. Dependence of luminescent characteristics on heat treatment temperature and heat treatment time for Sr2-xBaxSiO4∶Eu2+ (0≤x＜0.5) were also carefully studied. Heat treatment at 1 250 ℃ for 2 h is the best synthetic conditions in order to achieve the ideal characteristics of phase purity, grain morphology and grain size and to obtain the best luminescent characteristics. With the help of above systematic optimizing experiments the light conversion efficiency of the Sr2-xBaxSiO4∶Eu2+ silicate phosphors can achieve 95% of that of YAG phosphor. Other optical parameters of the silicate phosphors LED, such as color rende-ring index, color temperature and color purity are also comparable with that of YAG LED. The Sr2-xBaxSiO4∶Eu2+ silicate phosphors also have broader adaptive range for different chips and have more red component in the emission spectrum than that of YAG phosphor. The above research indicated that Sr2-xBaxSiO4∶Eu2+ is a potential candidate used as a conversion phosphor for white-light LEDs, especially suitable for manufacture of warm white-light LEDs.