ZnO微纳米结构的制备及其光学性能

在没有催化剂的情况下,空气中直接加热氧化锌片成功制备出ZnO纳米线/纳米片.通过改变反应温度,分别能够获得紧密排列的ZnO纳米线和纳米片.ZnO纳米线和纳米片的直径为几个微米,厚度约为280 nm.室温光致发光测试研究表明其最大可见发射波长在508 nm.该研究工作为纳米器件研制提供了一种简单直接氧化方法,可望高产率制备高质量半导体纳米线和纳米片阵列.     

ZnO纳米线阵列的可控生长及机理分析

为了研究一维氧化锌(ZnO)纳米线阵列的可控生长及生长机理,以二水合醋酸锌和六次甲基四胺为原料、生长氧化锌籽晶层的导电玻璃(ITO)为衬底,采用低温水热法实现大面积ZnO纳米线阵列的取向生长。通过扫面电镜(SEM)对获得的ZnO籽晶层和纳米线阵列进行表征,测试结果表明籽晶层的热处理温度、生长液的浓度对纳米线阵列的尺度分布有着明显的影响,但后处理温度对ZnO纳米线阵列的尺度分布几乎没有影响。     

ZnO纳米颗粒的分散及光致发光特性

利用火焰喷雾法成功制备了ZnO纳米颗粒,通过对样品的X射线衍射谱（XRD）和场发射扫描电子显微照片（FESEM）分析,发现制备的颗粒大小较为均匀,直径在10-20nm左右;结合多种物理方法对样品进行分散处理后,FESEM表征显示颗粒间的团聚得到较好改善;光致发光谱表明随着颗粒尺寸的减小,样品的紫外发光和可见发光的强度逐渐增强．     

红色光致发光材料ZnO:Li+的制备研究

目前对光致辐射红光的发光材料研究较少，且掺杂元素多为稀土。本文根据半导体掺杂原理，以氧化锌为基质、非稀土金属锂为掺杂元素，采用溶胶一凝胶法，合成了纳米级的红色光致发光材料ZnO：Li^ 。通过比较产品的发光性质，确定了反应的最佳煅烧温度为700℃，掺杂Li^ 的最佳摩尔浓度为0．2％。利用X-射线衍射仪和激光粒度分析仪分别对合成产物的结构和粒径进行分析，其平均粒度为62nm，发射光谱波长在615nm左右，说明掺杂元素锂固溶于ZnO晶体中形成了ZnO：Li^ 的纳米粉体。经荧光光度计测定合成产物的激发光谱与发射光谱，确定合成粉体的光致发红光的特性。文章最后对合成产物的光致发光机理进行了探讨。     

ZnO/PVP纳米复合膜的光学特性

采用高分子网络原位合成法制备了ZnO/PVP纳米复合膜.并且通过多种测试手段对ZnO/PVP纳米复合膜的光学特性进行了分析.通过XRD,TEM的测试结果可知,以聚乙烯吡咯烷酮(PVP)为模板,原位合成ZnO纳米粒子,具有六角纤锌矿结构;分散性好,粒径分布窄等特点;从光致发光谱中可以看出由于PVP的引入,使得ZnO纳米粒...     

氨气退火对ZnO纳米线阵列光致发光性质的影响

采用水热方法在Si（100）衬底上制备ZnO纳米线．利用提拉法在Si衬底上首先制备ZnO晶种层,然后利用水热法在晶种层上生长ZnO纳米线．在不同温度下的NH。气氛中,对zn0纳米线进行退火处理．系统地研究了NHs退火对ZnO纳米线光学性质的影响,在低温光致发光光谱中观察到了-9氮受主相关的光发射,并通过自由电子一受主辐射复合光发射确定受主离化能为129meV．实验结果还表明,随着退火温度的升高,施主一受主对辐射复合发光呈现了微弱红移现象．在700℃退火的条件下制备的ZnO纳米线的低温PL谱中,观察到较为明显的自由激子光发射,并采用理论拟合进行证明．     

表面活性剂对氧化锌微纳米晶形貌及光致发光性能的影响

以硝酸锌、氢氧化钠为原料,采用水热法制备出氧化锌微纳米晶,并研究了表面活性剂对氧化锌微纳米晶形貌的影响,探讨了不同形貌氧化锌微纳米晶的生长机理。采用X射线衍射(XRD)、扫描电子显微镜(SEM)以及光致发光谱(PL)等测试手段对产物的结构、形貌和光学性能进行了表征。结果表明,借助表面活性剂CTAB、SDBS、PVPK90可分别制得片状、棒状和花状纤锌矿型氧化锌微纳米晶,3种形貌的氧化锌微纳米晶均具有光致发光特性,尤其片状ZnO微纳米晶的光致发光峰最强。     

Eu~(3+)掺杂ZnO纳米粒子的制备及发光性能研究

采用溶胶-凝胶法,在温和条件下以无水乙醇做反应溶剂制备出了Eu3+掺杂的ZnO纳米粒子,粒子呈纺锤体形,长度约为70nm,宽度为40nm,长径比为1.8。XRD分析表明,ZnO∶Eu粒子为六方晶系结构,结晶良好,Eu3+的掺杂并没有改变其晶型结构。通过EDS得到了晶体中Eu3+与Zn2+的物质的量的比;通过荧光光谱仪测定其荧光性能,结果表明,其荧光光谱具有2个Eu3+的特征峰,分别位于595nm和617nm,且在n(Zn2+)∶n(Eu3+)=100∶3时,Eu3+特征峰最强;通过对样品荧光光谱的分析,证明了ZnO基质和Eu3+发光中心存在能量传递。     

燃烧法氧化锌晶须制备及其光致发光性能研究

在没有任何催化剂和添加剂的情况下,采用燃烧法制备了四脚状、多脚状、六棱柱状氧化锌晶须。讨论了反应温度对氧化锌晶须结构的影响,探讨了反应室内锌挥发度对氧化锌晶须形貌的影响。采用X射线衍射仪、电子扫描显微镜和荧光分光光度计对产物结晶结构、形貌和光致发光性能进行表征。研究结果表明：四脚氧化锌晶须的最佳生长温度为940℃;在880℃相对低温下,生成大量六棱柱形氧化锌晶须;在1 000℃下生成细长多脚状氧化锌晶须;在360 nm激发光作用下,发出波长约为520 nm的绿光。     

ZnO纳米阵列的水溶液法制备及其荧光特性

采用简单的低温水溶液法,在修饰有ZnO种子膜的玻片上制备出形貌规整、取向性较好的ZnO纳米棒阵列。利用场发射扫描电子显微镜(FE-SEM)、X射线衍射仪(XRD)和荧光测试仪(PL)等对产物的形貌、结构、光致发光特性进行了表征。结果表明,水热生长12 h后,能够得到均匀致密、高度取向的氧化锌纳米棒阵列,每个纳米棒直径大约为150 nm,长度为1.5μm左右。XRD结果显示,ZnO纳米棒的结构为纤锌矿结构,并沿c轴择优生长。荧光测试结果显示,所制备的ZnO纳米棒阵列在383 nm附近有一个强的紫外发射峰,同时在可见光区出现比较弱的蓝绿光发射峰。     

Low temperature doping of ZnO nanostructures

Doping of ZnO nanostructures was investigated by using a low temperature electrochemical process. Various dopant materials have been studied, including transition metals, group I, and group VII elements. The structure, composition, and optical properties of the doped ZnO nanostructures were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence, and x-ray diffraction. It was demonstrated that dopant elements were incorporated into the ZnO structures. The effects of dopant incorporation on the structure and properties of ZnO were also investigated. This low temperature approach is compatible with current micro-fabrication techniques and promising for large-scale production of doped ZnO nanostructures for optical and electronic applications.     

纳米氧化锌的制备与光学性能表征

用水热法以十二烷基磺酸钠(SDS)为添加剂制备了氧化锌纳米晶,并通过X 射线衍射(XRD)、高分辨透射电镜(HRTEM)、红外光谱(IR)、紫外 可见吸收光谱(UV)以及光致发光光谱(PL)等测试手段对所得产物形貌和光学性能进行了研究.TEM结果表明,所得产物为六角纤锌矿型氧化锌,直径约4 0～6 0nm ,分散性良好.PL光谱表明所制备的氧化锌样品在4 0 5nm处有一紫光发射峰,在约6 0 4nm处有一红光发射峰.我们认为4 0 5nm紫光发射是由锌空位引起的,红光的发射则是由氧填隙引起的     

Controlled growth of ZnO nanorods by polymer template and their photoluminescence properties

A large amount of one-dimensional ZnO nanorods with diameters in 15―50 nm aligned in radial cluster were successfully synthesized by polar polymer polyvinyl alcohol (PVA) as soft-template. The growth of ZnO nanorods was controlled by changing annealing temperature. The evolution of the morphology and microstructure was investigated by scanning electron microscope, transmission electron micro- scope and X-ray diffraction. It is shown that ZnO nanorods tend to be uniform and the crystallization is gradually i...     

Controlled growth and photoluminescence of highly oriented arrays of ZnO nanocones with different diameters

Large-scale oriented ZnO nanocone arrays were directly grown on zinc substrate through a hydro-thermal reaction of Zn foil with aqueous butylamine solution(3 mol/L) at 100—180 ℃ for 12 h.The syn-thesized products were characterized with X-ray diffraction,Raman spectrum,scanning electron mi-croscopy and transmission electron microscopy.The results showed that the ZnO nanocones were single crystalline with the wurtzite structure and grown along the [0001] direction.The diameter of nanocones is decreased with ...     

Shape controlled synthesis and growth mechanism of one-dimensional zinc oxide nanomaterials

Some types of ZnO nanostructures with various shape and size, including tetrapod-like ZnO (T-ZnO) nanorods, nanowires and nanoribbons, have been obtained by controlled growth process. The nanostructures of ZnO have been investigated by means of field-emission scanning electron microscope, transmission electron microscopy and high-resolution transmission electron microscopy. The growth mechanisms of various ZnO nanostructures were proposed and discussed.     

Mechanical properties of Mn-doped ZnO nanowires studied by first-principles calculations

First-principles calculations were performed to investigate the mechanical properties of ZnO nanowires and to study the doping and size effects.A series of strains were applied to ZnO nanowires in the axial direction and the elastic moduli of ZnO nanowires were obtained from the energy versus strain curves.Pure and Mn-doped ZnO nanowires with three different diameters (1.14,1.43,and 1.74 nm) were studied.It is found that the elastic moduli of the ZnO nanowires are 146.5,146.6,and 143.9 GPa,respectively,which are slightly larger than that of the bulk (140.1 GPa),and they increase as the diameter decreases.The elastic moduli of the Mn-doped ZnO nanowires are 137.6,141.8,and 141.0 GPa,which are slightly lower than those of the undoped ones by 6.1％,3.3％,and 2.0％,respectively.The mechanisms of doping and size effect were discussed in terms of chemical bonding and geometry considerations.