LiNi0.8-xAlxCo0.2O2制备与电极性能的研究

采用高温固相反应法合成具有良好层状结构的LiNi0.8-xAlxCo0.2O2。研究发现，LiNi0.71Al0.02Co0.2O2材料经20次循环弃放电后，其放电容量仍达152mAh/g，是首次放电容量的97.4%。通过XRD结构测量、慢扫描循环伏安测试和电极经多次循环后其交流阻抗测试的对比，表明对LiNiO2进行Al和Co共掺杂，增强了材料层状结构的稳定性，有效地抑制了Li^ 嵌入脱出过程中材料的相转变，其充放电性能、耐过充性和循环性能都得到明显改善，热分析测试表明，在高脱锂状态下共掺杂材料的热稳定性也有所提高。     

掺杂金属离子改性的TiO2薄膜光催化剂的研制

采用溶胶-凝胶法制备TiO2薄膜光催化剂，着重考察了掺杂铈、镧、钨等金属离子改性的TiO2薄膜的光催化活性，研究了其紫外-可见光透过性能，甲基橙水溶液的光催化降解实验表明：掺杂铈、镧、钨三种金属离子后，TiO2薄膜的光催化活性均有不同程度的提高，最佳掺杂浓度分别为3．0％、1．0％、0．5％，其中掺杂铈的TiO2薄膜光催化活性最高。     

基于N-乙基咔唑-2-乙烯基-8-羟基喹啉锌的黄绿色有机电致发光器件的性能

通过用一种既具有空穴传输特性又具有发光特性的新型荧光染料N-乙基咔唑-2-乙烯基-8-羟基喹啉锌((E)-2-(2-(9-ethyl-9H-carbazol-3-yl)vinyl) quinolato-zinc, CzHQZn)作为受主, 制备了结构为ITO/2T-NATA (30 nm)/CBP: 6%Ir(ppy)3:wCzHQZn(20 nm)/Alq3(50 nm)/LiF/Al(ITO: indium-tin oxide, 2T-NATA: 4,4',4'-{N,N-(2-naphthyl)-N-phenylamino}-triphenylamine, CBP: 4,4-N,N'-dicarbazole-biphenyl, Ir(ppy)3: factris (2-phenylpyridine) iridium, Alq3: tris(8-quinolinolato) aluminum; w 是CzHQZn 的质量分数)的黄绿色有机电致发光器件(OLEDs). 研究了掺杂体系在不同掺杂浓度(w=5%、10%、12%、15%)时的电致发光(EL)特性. 结果表明, CzHQZn 掺杂浓度为10%的器件在11 V 电压下实现了黄绿光发射, 色坐标为(0.4045, 0.5113), 最大发光亮度为16110 cd·m-2; 而在7 V电压下的最大发光效率为2.19 cd·A-1, 最大外量子效率为0.775%.     

溶胶-凝胶-微波法制备阴阳离子同时掺杂型LixMn2OyFz

以LNO3、L iF和MnNO3为原料,通过控制n(L i)/n(Mn)和掺F量,运用溶胶-凝胶-微波法在750℃下合成阴阳离子复合掺杂型L ixMn2OyFy电极材料。XRD和FTIR实验表明,适量的阴阳离子复合掺杂不改变材料的立方尖晶石结构;掺杂适量的锂可以改善材料的循环性能,而氟不但可以起到保持材料的比容量而且可以显著降低材料在高温条件使用时的容量损失;充放电和循环伏安实验均证明,L i1.06Mn2O4.034F0.10是较理想的电极材料。室温条件下,L i1.06Mn2O4.034F0.10首次放电比容量达到119mAh/g,循环20次后比容量仍保持在115mAh/g,在55℃使用时,材料20次的比容量损失率为5.6%     

稀土元素Lu，Sc掺杂GaN光电特性的第一性原理研究

基于密度泛函理论,采用广义梯度近似（GGA+U）平面波超软赝势方法,计算了本征GaN和稀土元素Lu、Sc掺杂GaN体系的电子结构和光学性质.结果表明：计算得到本征GaN的禁带宽度为3.37 eV,与实验值（3.39 eV）接近. Lu掺杂后GaN体系带隙变窄,而Sc掺杂后诱导了深能级杂质,带隙变宽,但仍为直接带隙半导体.掺杂后体系均发生畸变,晶格常数和体积增大,且在费米能级附近产生杂质带. Lu、Sc掺杂GaN体系的静态介电常数较本征GaN（4.50）均有所增大.Lu、Sc掺杂后体系介电常数虚部整体左移,光吸收边往低能方向移动,发生了红移现象.计算结果对稀土元素Lu、Sc掺杂GaN高压光电材料的开发和研究提供了理论依据.     

掺杂PVK薄膜中两种组分相互作用的光谱及形貌研究

将两种荧光材料Alq₃和DCJTB 同时掺杂到聚合物PVK中,通过混合薄膜的光学及电学性质研究了能量传递过程及电荷陷阱作用。同时用AFM分析了不同掺杂浓度下混合薄膜的相分离现象。发现随着DCJTB染料比例的增加,两种染料在PVK中的分散越来越均匀,说明在双掺杂体系中存在Alq₃和DCJTB 的某种作用,这种作用打散了混合物中Alq₃的聚集,但随着掺杂浓度的进一步增加,DCJTB形成了自己独立的电荷传输通道,从而降低了电致发光器件的启亮电压。     

XRD Analysis on the Fluorescence Material of Sm Doped Si-Ca-Mg System

Fluorescence material of Sm doped Si-Ca-Mg system was synthesized by using the method of solid phase reaction at high temperature. The phase composition and crystal structure of this material were analyzed with XRD method for its composition and the existence form of Sm atom. We aimed to exactly determine the phase composition of this fluorescence material and the doping position and environment of rare-earth Sm atom in the system because these factors have significant effects on the properties. The analytical results show that the Sm atoms dope in Ca2O26Si6Sm8 lattice in the form of atomic site-occupation in three different space positions with different occupancy rates. Therefore, based on the XRD analytical results, the fluorescence material of Sm doped Si-Ca-Mg system with high performance can be synthesized.     

金MPC掺杂琼脂-明胶复合泡沫的均匀性研究

 采用表面包覆水溶性硫醇单分子层的金团簇（MPC）对琼脂-明胶复合泡沫进行掺杂。研究表明,掺杂泡沫轴向密度均匀,金MPC粒径小,不聚焦,在泡沫中分散良好,掺杂对泡沫微观形貌没有明显影响。当掺杂泡沫密度低至5.8 mg/cmcm³,、掺杂质量分数高达30%时,金MPC在复合泡沫中不发生沉降或聚集。以水作溶剂,成功制得密度小于10 mg/cm³,孔径小于100 mm的金MPC掺杂琼脂-明胶泡沫靶材料。     

Nd crystal-field study of weakly doped Nd1−xCaxMnO3

Nd³⁺ crystal-field excitations in Nd_1−xCa_xMnO₃ (x=0.025, 0.05 and 0.1) single crystals are studied via infrared transmission as a function of temperature and external magnetic field. We report excitations associated with Nd³⁺ sites as detected in NdMnO₃ and excitations due to Ca doping. The latter reveal phase separation between the usual A-type antiferromagnetic states and the insulating canted (ferromagnetic) spin states in the vicinity of doped Ca²⁺ ions. Both Nd³⁺ crystal-field levels could be described using calculated parameters for NdMnO₃. Also, while oxygen stoichiometry and coherent Jahn–Teller distortions seem not to be affected by Ca doping, increased absorption bandwidths characterize the doped crystals.     

Electromagnetic and microwave absorbing properties of Co2Z-type hexaferrites doped with La

Z-type ferrites doped with La³⁺, Ba_3−xLa_xCo₂Fe₂₄O₄₁ (x=0.00-0.30), were prepared by sol-gel method. The effect of the substitution La³⁺ rare-earth ions for Ba²⁺ ions on the microstructure, complex permeability, permittivity and microwave absorption of the samples was investigated. The results show that the major phase of the ferrites changed to Z-phase when sintering temperature was 1250 °C for 5 h. With the increase of the substitution ratio of La³⁺ ions from 0.0 to 0.3, the lattice parameters a and c increased gradually, which resulted in the change of the particle shape and size. The data of magnetism showed that the addition of La³⁺ ions make the ferrite a better soft magnetic material due to increase of magnetization (σ_s) and decrease of coercivity (H_c). The La³⁺ ions doped in the ferrite not only improved complex permeability and complex permittivity, but also microwave absorbency.