真空热蒸发制备ZnS薄膜及其特性的研究

用真空热蒸发在不同衬底温度下制备了ZnS薄膜,利用X射线衍射(XRD)、X射线能谱(EDAX)、紫外可见分光光度计(UV-vis)和原子力显微镜(AFM)研究了ZnS薄膜的晶体结构、成分、光学性能和形貌,分析了衬底温度对ZnS薄膜结构与光学特性的影响。结果表明,所制备的ZnS薄膜呈立方闪锌矿结构,衬底温度为300℃所制备的ZnS薄膜原子比(S/Zn)为0.95/1;薄膜表面均匀致密,呈多晶态,晶粒尺寸为18.2nm;在可见区有好的透射性能,光学禁带宽度为3.82eV。     

荧光粉在高显色白光LED中的应用技术研究

采用蓝光LED芯片作为激发光源,通过封装试验研究了荧光粉发射波段、蓝光芯片波段、白光LED色温和显色指数的关联性。在分析单一组分荧光粉制作的白光LED的基础上,进一步对双组分荧光粉方案进行了试验研究。结果表明当采用绿光荧光粉配合橙黄光荧光粉的双组分方案后,在光效较普通白光LED下降幅度小于15％的情况下,显色指数Ra得到显著提升（86．7）。     

革命者：中国LED照明专辑——以燃烧合成工艺制备白光LED用（Ca,Y）-α-SiAlON：Eu陶瓷荧光粉

利用机械活化辅助的燃烧合成方法制备了稀土元素Eu掺杂的（Ca，Y）-α-SiAlON陶瓷荧光粉。采用X射线衍射仪（XRD）。扫描电子显微镜（SEM）和光致荧光光谱仪（PL）对合成产物进行了分析，结果表明，合成出的产物由平均粒度小于5μm的a—SiAlON粉末颗粒组成。该粉末在日光下呈黄绿色。在蓝光和近紫外光波段有宽的激发峰，对应的发射峰中心位于绿光至黄光波段，从而可以配合蓝光或近紫外光LED使用。制成白光LED光源。     

微波加热法制备YBO3：Eu^3＋荧光粉

首次用微波加热法成功制备了YBO3：Eu^3＋荧光粉,分别用X射线衍射（XRD）、扫描电镜（SEM）、激光粒度仪对产物的晶相、形貌和粒度进行表征,用光致发射光谱（PL）对产物的发光性能进行研究。结果表明,样品为单一六方结构的YBO3,形貌完整,粒度分布均匀,D50=1．84μm,PL谱呈现Eu^3＋的特征发射峰,最强峰为593nm的红色发射峰。     

硅酸盐橙红色荧光粉的制备与发光性能研究

通过高温固相合成法制备了高效橙红色荧光粉Sr2.96Eu0.04SiO5,研究了烧结温度、保温时间、助熔剂含量对荧光粉发光性能的影响。通过XRD和光谱测试表征得出：最佳的烧结温度为1 500℃,保温时间为4h;当助熔剂H3BO3为3wt%含量时,荧光粉的结晶程度、发光强度最好。荧光粉的激发峰为宽带激发谱（300～500nm）,发射主峰为597nm。     

YPO4:Ce荧光粉的合成工艺及光谱特性

研究了采用共沉淀法制备出YPO4:Ce3+前驱体,并将该前驱体与一定量的助熔剂混合在高温箱式炉中合成了YPO4:Ce3+荧光粉。通过X射线粉末衍射(XRD)图谱及荧光光谱等手段,系统研究了灼烧温度、保温时间、不同助熔剂对荧光粉相对发射强度的影响。实验结果表明,当灼烧温度为1100℃、保温时间为1.5h、助熔剂Li2CO3的添加量为1.0wt%时获得的荧光粉相对发射强度最高。经激光粒度仪测试荧光粉的粒度D50为4.2m。     

钨酸锂铕荧光粉的制备及封装性能研究

文章简单介绍了钨酸锂铕（LiEuW2O8）荧光粉的制备方法,分析了该荧光粉的激发光谱、发射光谱的测试结果。该荧光粉具有较宽的激发光谱,适合与近紫外、蓝光以及绿光芯片配合使用。其发射光谱主峰位于615nm,色坐标位于（x=0．666,y=0．331）左右,具有较高的色纯度。通过分别对钨酸锂铕荧光粉及硫化物荧光粉进行封装,发现该荧光粉能有效降低色温,且对光效影响较小,适于低色温白光LED封装。     

Gd_2MoO_6:Sm~(3+)荧光粉的制备及其发光性能研究

实验采用高温固相反应法制备了Gd_2MoO_6:Sm荧光粉,并通过X射线衍射仪和荧光分光光度计对荧光粉的结构和发光性能进行了表征,重点采用控制变量法研究不同种类助熔剂对荧光粉结构影响规律。结果表明,Gd_2MoO_6:Sm~(3+)荧光粉在紫外波段可被有效激发,发射峰值波长位于566 nm、603 nm和655 nm处;掺入少量的助熔剂不会改变荧光粉本身的晶体结构,采用适量的氟化钡(BaF_2)或氯化钡(BaCl_2)能够大幅度提升荧光粉的发光性能。     

照明用LED相关专利摘要

本发明提供了一种用于白光LED用途的绿色、黄绿色或黄色荧光粉,其化学式是(Tb3-a-bM’aCeb)(Al5-cM"c)O12,其中M’是Y、Lu、Gd、La、Pr、Sm、Dy和Yb中的一种或两种以上;M"是Ga、Ge、B、SiI、n、Zn中的一种或两种以上;0≤a<3,0.01≤b≤0.3,0≤c≤5。本发明所制备的荧光材料具有钇铝石榴石的晶体结构,且被波长为430~480nm的蓝光激发光源如LED激发时,能发射波长为538~585nm的高亮的荧光。本发明还提供了用所制备的荧光粉配合蓝光LED制成的白光LED电光源。本发明还涉及该荧光粉的制备方法。     

Eu_2Mo_4O_(15)∶Gd~(3+)在465nm蓝光激发下的红色发光

采用简单的沉淀法制备了白光LED用Eu_2Mo_4O_(15)∶x%Gd~(3+)(x=0,20,40,60)系列荧光粉。在465 nm蓝光激发下,该荧光粉发射强的红光,而且发射强度与Gd~(3+)的掺杂浓度密切相关。当Gd~(3+)浓度为40%时,激发效率和发光效率最大。热特性的研究表明,40%Gd~(3+)掺杂样品的热猝灭激活能约为0.55 eV。~5D_0和~5D_1到电荷迁移带(CTB)的热激发是导致发光热猝灭的主要因素。     

Photocatalytic Degradation of MB with Yeast-supported ZnS Hybrid Microspheres

Yeast cells were utilized as novel bio-carriers in the synthesis of yeast/ZnS (YC/ZnS) composite microspheres in this paper. The as-produced particles are characterized by SEM, TEM and XRD. Employing the as-obtained YC/ZnS hybrid as new photocatalysts, we studied the main influencing factors in the photocatalytic degradation of low concentration methylene blue wastewater. The results indicated that the ZnS hybrid particles were of core-shell structure with the 450–500 nm shell of ZnS covering yeast carriers. In the degradation experiments, pH, dosage of YC/ZnS and UV illumination distance had significant influence on the degradation of methylene blue wastewater. The degradation rate reached 95.2% under the optimal conditions when 10 mg/L methylene blue aqueous solution was photocatalyzed with 3g/L YC/ZnS at pH8, 20–30°C and illumination distance 50 cm.     

Luminescence Enhancement of ZnS:Cu Nanocrystals by Zinc Sulfide Coating with Core/Shell Structure

Via wet chemical method with organic assistant, ZnS:Cu/ZnS core/shell structure was prepared. X-ray diffraction measurements showed that ZnS:Cu was formed with zinc blende structure, and ZnS shell growth on the surface was indicated through a red-shift in the UV-Vis absorption spectra with increasing particle size. The emission peak at about 510 nm was observed, which should be assigned to recombination of an electron from the shallow delocalized donor levels at the t₂ level of Cu²⁺ centers. As passivation layer, effect of ZnS shell on luminescence intensity and lifetime of ZnS:Cu were investigated. Comparing with uncoated ZnS:Cu, ZnS shell really enhanced the luminescence intensity and lifetime significantly, which resulted from the reduction of nonradiative recombination sites.     

红色荧光粉LiW_2O_8:Eu的制备及其发光性质

采用高温固相反应法制备了Li(4-3x)W2O8:Eux系列钨酸盐红色荧光粉,探讨了其合成工艺条件,确定了Eu3+的最佳含量为x=1,试样的最佳反应温度为850℃。该荧光粉具有较宽的激发光谱,适合与近紫外、蓝光芯片配合使用。其发射光谱主峰位于615nm,色坐标位于(X=0.666,Y=0.331)左右,具有较高的色纯度。因此,这种荧光粉是一种可能应用在白光LED上的红色荧光粉材料。     

不同波长光激发下氧化锌纳米线的发光特性研究

用汽相传输法制备了氧化锌(ZnO)纳米线,并在室温条件下,测量了在不同波长光的激发下,样品的光致发光谱.实验结果表明,当用325 nm的光激发ZnO纳米线时,观察到峰值波长约为392 nm的紫光峰峰值强度强,峰值波长约为445 nm的蓝光峰峰值强度较弱和峰值波长约为486 nm的蓝绿光峰峰值强度弱;当增加激发光波长到380 nm时,发射光谱变成峰值波长约为520 nm的半高宽较宽、峰值强度较强的带状光谱.同时对发光峰产生的机理进行了分析.     

缺陷对多壁碳纳米管光致发光特性的影响

采用化学气相沉积法,在反应温度分别为980℃和1040℃时制备了多壁碳纳米管（MWNTs）样品,并采用扫描电镜和拉曼光谱对样品进行了表征;结果表明,当反应温度为9800C时,制备的碳纳米管结构缺陷更多。使用波长为350nm的光激发2种样品并测量它们的光致发光光谱。发射峰值约在550nm处,反应温度为980℃时制备的碳纳米管的发射光谱的光强较强。     

Microstructure and electroluminescence of ZnS:Cu,Cl phosphor powders prepared by firing with CuS nanocrystallites

This paper presents the microstructure and electroluminescent performance of ZnS:Cu,Cl phosphor powders prepared by firing micrometer-sized ZnS with NaCl and CuS nanocrystallites at 900^∘C in the reducing atmosphere. A series of samples with Cu addition ranging from 40 to 5000 ppm were studied. XRD analysis showed that ZnS:Cu,Cl samples with Cu addition of ≥400 ppm exhibited a transformation from hexagonal to cubic structure. The whole series of ZnS:Cu,Cl samples showed significant photoluminescent (PL) intensity; however, only samples with Cu addition of ≥400 ppm revealed measurable electroluminescent (EL) intensity. This difference was supposed to be a result of nano-sized Cu_xS precipitation in ZnS during firing treatment, where Cu_xS acted as electron emission source to enhance the EL intensity. Furthermore, ZnS:Cu,Cl powder sections were analyzed using X-ray mapping (XRM) of a scanning transmission electron microscope, revealing that Cu_xS precipitates of 50–80 nm in size were observed only in the samples with EL emission, i.e. Cu addition ≥400 ppm. The variation of EL intensity was interpreted in terms of the concentration of Cu activators as well as the phase and the amount of Cu_xS in ZnS.     

白光LED用Li2+y(Gd1-xEux)4（MoO4）7-y（BO3）y新型红色荧光体

首次报道了采用高温固相反应合成Li2+y(Gd1-xEux)4(MoO4)7-y(BO3)y(0相似文献   

InGaN-based ultraviolet emitting heterostructures with quaternary AlInGaN barriers

Nitride-based ultraviolet (UV) heterostructures with InGaN quantum wells and AlInGaN barrier layers have been grown by metal-organic chemical vapor deposition on sapphire substrates. The emission band was at 3.307 eV (375 nm) at room temperature (RT) and its full-width at half-maximum was /spl sim/82meV. In addition to the UV band, some blue emission admixture was found in a single-quantum-well (SQW) structure, which the authors attribute to recombination of injected electrons that are not captured into the SQW and enter the p-side of the structure. The authors demonstrate a significant advantage in utilizing multiple-quantum-well (MQW) structures that provide a more effective capture of injected carriers into wells and predominance of UV emission. Temperature-sensitive competition between two emission mechanisms in MQW structures has been observed. Below /spl sim/170 K, the blue impurity-related emission dominated. In the 170-190 K range, an anomalous temperature-induced "blue jump" by over /spl sim/340 meV to UV region occurred, with UV emission dominating above 190 K.     

LED峰值波长对多光谱组合白光色参数的影响

多光谱组合的LED在动态照明、光环境、医疗、健康等领域具有广泛的应用前景,但是其光度和色度的一致性和稳定性极大影响着这类技术方案的应用前景。采用6种单色LED使用光谱组合的方式构建了典型色温5500 K和2700 K的白光器件,并对组成白光的单色LED的光谱稳定性进行了分析,仿真实验研究了多种单色LED峰值波长的漂移对色温、显色指数和色坐标的影响。实验表明,红色630 nm和橙色590 nm附近的峰值波长漂移对于色温的影响最大,漂移2 nm左右即可导致色温100 K左右的变化;橙色590 nm的峰值波长漂移对于显色指数的影响最大,在漂移2 nm左右即可导致显色指数的变化大于2;在5500 K附近x坐标的最大变化量0.016出现在红光631 nm的波长变化中,y坐标的最大变化量0.015出现在宝蓝色480 nm的波长变化中;在2700 K附近,x坐标的最大变化量0.016出现在橙色590 nm和红色631 nm的波长变化中,y坐标的最大变化量0.017出现在橙色590 nm的波长变化中。