Sn掺杂ZnO纳米带的制备及其光致发光性能研究

采用热蒸发法制备了单晶Sn掺杂ZnO纳米带,其中Sn的掺杂含量约为5%(原子分数).X射线衍射(XRD)结果表明Sn掺杂ZnO纳米带为单相纤锌矿结构.X射线光电子能谱(XPS)表明样品中Sn的价态为4+.样品的室温光致发光谱(PL)在445.8nm处存在较强的蓝光发射峰,对其发光机制进行了分析.     

一种P掺杂ZnO纳米梳的制备及其光致发光性能研究

采用化学气相沉积(CVD)方法制备了P掺杂ZnO纳米梳,扫描电子显微镜(SEM)结果显示,纳米梳状产物均匀分布在Si衬底上。P掺杂ZnO纳米梳为高度结晶的六方纤锌矿结构,ZnO中P的掺杂含量约为2%(原子分数)。室温光致发光(PL)光谱表明,P掺杂ZnO纳米梳在样品不同区域的发光性能略有不同,但是均出现3个发光峰:紫外、绿光和近红外发光峰。同时PL结果也表明样品的整体结晶质量比较好。     

Ce掺杂ZnO光催化剂的制备及性能

采用共沉淀制备了稀土Ce掺杂ZnO光催化剂;利用X射线衍射（XRD）、扫描电子显微镜（SEM）等对光催化剂进行表征;考察了不同NaOH用量制备的催化剂光催化对亚甲基蓝脱色降解性能的影响。结果表明,ce的掺杂有利于抑制光生电子-空穴的复合,显著提高ZnO的光催化性;NaOH用量和Ce掺杂量对光催化剂的微观形貌和光催化活性有较大影响;制备过程中金属离子总量（Ce^3＋＋Zn^2＋）与OH-摩尔比为1：2．5,掺杂量为2％（摩尔分数）时,制备的催化剂主要微观形貌为具有层状微球结构,光催化性能良好。     

Pd掺杂纳米ZnO的燃烧法制备及性能研究

以酒石酸为燃料,硝酸锌为氧化剂,采用溶液燃烧法制备了Pd(0~7%(原子分数))掺杂纳米Zn O。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和荧光光谱仪对产物了进行表征,重点讨论了掺杂对Zn O气敏性能的影响。结果表明,在330℃测试条件下,纯Zn O和7%(原子分数)Pd掺杂Zn O气敏元件对体积分数为5.0×10-5的乙醇气体灵敏度分别为21.4和11.2;元件对5.0×10-5丙酮气体的灵敏度分别为2.0和8.8。Pd掺杂显著提高了元件对乙醇和丙酮气体的选择性。     

纳米ZnO的光催化和光致发光性能

纳米ZnO的制备方法、生长机理、性能及应用已被广泛研究并取得很大进展,尤其是纳米ZnO的光催化降解及光致发光因具有广阔的应用前景而引起高度重视.着重介绍了目前国内外ZnO纳米粒子的光催化、降解和纳米线/棒的光致发光性能的研究及成果.     

Cu掺杂ZnO的光致发光光谱

ZnO是宽禁带半导体,室温下禁带宽度为3.37eV,激子束缚能高达60meV,是制备光电器件的优选材料。然而,p型掺杂仍是亟待解决的问题。ⅠB元素Cu被认为在ZnO中产生受主能级,可以实现ZnO的p型掺杂。综述了各种制备方法、制备条件和激发条件下得到的Cu掺杂ZnO薄膜、纳米线和纳米棒的光致发光谱和机理,总结出Cu掺杂ZnO光致发光谱的带边发射会因为Cu的掺杂强度降低,或出现发射中心红移等现象。可见光区域由于Cu掺杂会产生新的蓝光、绿光和橙光发射峰,蓝光发射峰可能与Cu2+-Cu+跃迁或VZn和Zni有关;绿光发射峰可能与Cu杂质或VO-VZn跃迁有关,Cu掺杂还可能引入非辐射复合的点缺陷中心;橙光发射峰则可能由于Cu杂质受主能级向深施主能级跃迁而产生。     

ZnO纳米晶薄膜的制备及特性分析

在低温下制备了粒径小于10nm的ZnO纳米晶,用旋涂法制备ZnO纳米晶薄膜,XRD分析ZnO晶相是纤锌矿结构;SEM与AFM表明,纳米晶薄膜在300％退火后薄膜的厚度明显减小到130nm,表面粗糙度降低到3．27nm,粒径明显增大;紫外-可见吸收和透射比光谱表明,随着退火温度的增加,吸收边发生了红移,吸收肩更明显,薄膜具有高的透射率（75—85％）;薄膜方阻随温度增加而增大,300℃以下退火方阻增加很小（小于8．5Ω／sq）,400℃以上退火方阻大幅增加（大于21．1Ω／sq）,因此,ZnO纳米晶薄膜最优退火温度点为300℃。     

一维纳米结构ZnO掺杂的研究进展

ZnO是目前已知纳米结构中形态最为多样的多功能材料之一,其一维纳米结构的掺杂改性日益成为研究和应用的热点.本文按照杂质原子引入一维纳米结构ZnO晶格的先后,将ZnO的掺杂分为原位掺杂和后期掺杂两类,对当前一维纳米结构ZnO的掺杂进展进行了回顾,提出掺杂工艺中尚待解决的问题,并对其发展趋势及前景进行了展望.     

ZnO纳米锥光致发光性及印刷ZnO纳米锥场发射性能研究

利用物理热蒸发法制备大规模的蒲公英状的ZnO纳米锥,利用荧光光谱仪对ZnO纳米锥进行了光致发光性能测试.针对现有的丝网印刷碳纳米管(CNTs)薄膜需要各种后处理工艺后才能改善其场发射特性的问题,提出了一种不需任何后处理丝网印刷ZnO纳米锥的浆料配制工艺.用该工艺制备的丝网印刷ZnO纳米锥的场发射特性测试表明,ZnO纳米锥与制浆剂质量比为3∶5的薄膜的开启场强最低为2.25V/μm(电流密度为1μA/cm2),在4.6V/μm场强下,阳极荧光粉的发光点亮度高且分布均匀.说明该方法成本低,工艺简单,无需任何后处理,在ZnO纳米锥场发射显示器的制作中有很好的实际应用价值.     

Low-temperature growth and optical properties of Ce-doped ZnO nanorods

Ce-doped ZnO nanorod arrays were grown on zinc foils by a hydrothermal method at 180°C. The effects of Ce-doping on the structure and optical properties of ZnO nanorods were investigated in detail. The characterisation of the rod array with X-ray diffraction and X-ray photoelectron spectroscopy indicated that Ce³⁺ ions were incorporated into the ZnO lattices. There were no diffraction peaks of Ce or cerium oxide in the pattern. From UV-Vis spectra, we observed a red shift in the wavelength of absorption and decreased band gap due to the Ce ion incorporation in ZnO. The photoluminescence integrated intensity ratio of the UV emission to the deep-level green emission (I _UV/I _DLE) was 1.25 and 2.87, for ZnO and Ce-doped ZnO nanorods, respectively, which shows a great promise for the Ce-doped ZnO nanorods with applications in optoelectronic devices.     

Effect of doping precursors on the optical properties of Ce-doped ZnO nanorods

We have investigated the use of different cerium precursors for fabrication of Ce doped ZnO nanorods by electrodeposition. ZnO nanorods fabricated with different Ce precursors had similar morphology, but very different optical properties. The influence of annealing in oxygen at different temperatures on the optical properties of Ce doped ZnO nanorods was also studied. The as-grown samples exhibited very different ratios of ultraviolet to visible (defect) emission. The relative contributions of green and orange-red emissions in the emission spectra of annealed samples were also dependent on the precursor used, indicating that the types and concentrations of native defects were dependent on the precursor used. To explore the possibility of applications of these nanorods in ZnO-based devices, nanorods were also grown on p-GaN substrates. Two different Ce precursors in this case resulted in different current-voltage curves, as well as different electroluminescence and photoluminescence spectra of the devices. Obtained results are discussed.     

碱沉淀法制备Ce掺杂ZnO及其光催化性能

采用硝酸锌和硝酸铈为原料,三乙醇胺为沉淀剂,通过碱沉淀法制备了一系列Ce掺杂ZnO光催化剂。借助SEM,XRD,UV-vis等表征手段对催化剂的结构进行表征。以亚甲基蓝溶液脱色反应为模型,考察了不同Ce掺杂量ZnO光催化剂的光催化性能,结果表明,Ce掺杂ZnO的光催化性能高于未掺杂ZnO,且Ce掺杂量为2%时,ZnO光催化性能最好。最后简要讨论了Ce掺杂对ZnO光催化性能的作用机理。     

Spectroscopic properties of the Ce-doped borate glasses

The EPR, optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Ce-doped glasses with Li₂B₄O₇, LiKB₄O₇, CaB₄O₇, and LiCaBO₃ compositions have been investigated and analysed. The borate glasses were obtained from the corresponding polycrystalline compounds in the air atmosphere, using standard glass technology. The EPR signals of the isolated Ce³⁺ and pair Ce³⁺–Ce³⁺ centres, coupled by magnetic dipolar and exchange interactions were registered at liquid helium temperatures. The characteristic for glass host broad bands corresponding to the 4f → 5d transitions of the Ce³⁺centres have been observed in the optical absorption and photoluminescence (emission and excitation) spectra. The obtained luminescence decay curves can be satisfactory described by exponential function with lifetimes in the 19.8–26.1 ns range, which depend on the basic glass composition. The local structure of Ce³⁺ centres in the investigated glasses has been considered and discussed.     

Synthesis of Ce-doped GN/ZnO architectures with enhanced photocatalytic activity

The novel flower-like GN/ZnO architectures composed of curved cone are synthesized with hydrothermal method at 120?°C for 4?h. The GN/ZnO composite was doped with GN during preparation, the photocatalytic activity of GN/ZnO was evaluated by photodegradation of Rhodamine B (RhB) under simulated visible light. The results showed that the photocatalytic activity of α-CNTs/SnO₂ for degradation of RhB was up to 90% within 50?min, which was much higher than that of pure compound. It was significantly found that the introduction of GN, which may suppressed the recombination of photogenerated electron-hole pairs on the interface of SnO₂, leading to enhanced photocatalytic activity.     

电沉积法制备La掺杂ZnO薄膜及其光致发光性能

以乌洛托品为络合剂,采用电化学沉积法成功地制备出La掺杂ZnO薄膜.通过对样品的XRD表征,得出生长的样品为ZnO纤锌矿结构,(002)衍射峰随掺杂La3+浓度的增加而向更小角度方向移动,表明少量La3+掺杂进入了ZnO点阵结构中.EDS测量结果显示,La3+以替代的形式进入ZnO晶格中,掺入量为2.4%(原子分数)左右.由XPS测量结果可知,镧离子在薄膜中以+3价的形式存在,PL测量结果进一步证明了La3+能够取代ZnO晶格中Zn2+的格位.     

Photoluminescent properties of LiInO2 nanocrystals

Synthesis and luminescence properties of LiInO₂ nanocrystals by the sol–gel process were investigated. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectroscopy and absorption spectra. The well-crystallized tetragonal LiInO₂ can be obtained by heat treatment above 600 °C from XRD. The excitation wavelengths at about 246 nm were associated with charge transfer between In and O with In³⁺ ions in octahedral coordination. The PL spectra excited at 246 nm have a broad and strong emission band maximum at 391 nm, corresponding to the self-activated luminescence. The optical absorption spectra of the 600 °C sample exhibited the band gap energies of 3.7 eV.     

表面活性剂、pH对ZnO光致发光及光催化性能的影响

采用水热法制备了不同表面活性剂、不同pH值的ZnO。讨论了不同表面活性剂与pH值对ZnO光致发光及光催化性能的影响,同时研究了光催化时间对ZnO光催化性能的影响。结果表明：在反应温度180℃、pH=14下生成的ZnO（SDS）的平均粒径最小,为052um,光致发光性能较好,对次甲基蓝的催化降解作用最好,135min后降解率达到100％。     

Ce掺杂纳米WO3的制备及其气敏性能研究

在乙醇和水溶液体系中,以钨酸铵和硝酸铈为原料采用溶胶-凝胶法制得纳米级Ce掺杂的WO3粉体。用XRD测试了纳米颗粒的晶相和晶体结构,发现掺杂少量Ce的WO3粉体晶型单一,结晶度增强。用扫描电镜和比表面测试仪表征了WO3基纳米粉体。用TG-DTA测试5%Ce+WO3干凝胶,结果表明所制备的含吸附水和有机物的5%Ce+WO3纳米颗粒在450℃下反应完全。纯WO3和Ce掺杂的WO3厚膜元件对H2S有很好的灵敏度和选择性。与纯WO3元件相比,掺杂Ce的WO3元件在相对湿度RH=20%～70%有好的抗湿能力,稳定性增强。     

ZnO纳米棒Al掺杂和A1,N共掺杂的制备技术与光致发光性能

采用水热法首先合成了Al掺杂ZnO(AZO)纳米棒,在此基础上通过550℃的氨气氛中退火制备了Al,N共掺杂ZnO(ANZ())纳米棒.运用X射线衍射(XRD),场发射扫描电镜(FESEM),透射电子显微镜(TEM),X射线能谱(EDS)和光致发光(PL)对样品进行了表征与分析.结果表明,制备的AZO和ANZ()纳米棒...