共查询到20条相似文献,搜索用时 125 毫秒
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最近,通过对有机表面活性剂包覆的氧化锌纳米微粒ZnO/ST作强热表面化学修饰,我们得到了核心/壳层结构的红色氧化锌复合纳米微粒.与以往的无色氧化锌纳米微粒的性质相比,这种复合微粒具有独特的光学和非线性光学性质.1)复合氧化锌纳米微粒的光学带隙发生了很大红移.同体相带队相比(Eg=3.4eV),新的光学带隙出现在2.5eV左右,而且其光学带隙随着热处理温度的升高而向更长波方向移动.透射电子衍射成像和选区衍射实验表明,这种颜色变红的样品在粒径上(~8nm)与热处理前的无色样品相比没有明显的变化,且具有同体相氧化锌相… 相似文献
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不同粒径的SiO_2纳米粒子与PVK分子复合体系的发光性质研究 总被引:1,自引:0,他引:1
通过溶胶-凝胶的方法,在乙醇溶液中合成了40nm和60nm两种不同粒径的SiO2纳米粒子,并将其分别与聚乙烯咔唑(PVK)混和,得到了不同粒径、不同质量分数配比的PVK/SiO2纳米粒子复合体系;利用光致发光光谱、吸收光谱和喇曼光谱,深入研究了PVK分子在不同状态条件下的发光特性和PVK/SiO2纳米粒子复合体系的光学性质;在复合体系中,观察到PVK与SiO2纳米粒子之间的界面能量转移过程,且不同粒径的SiO2纳米粒子对PVK分子的发光性质影响也不同。通过喇曼光谱的进一步研究表明,SiO2纳米粒子的存在,使PVK分子的振动能量明显减小,表明PVK分子与SiO2纳米粒子表面存在较强的相互作用。 相似文献
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ZnO近紫外波长纳米激光器的研究 总被引:1,自引:0,他引:1
随着纳米科技的兴起,纳米激光的研究成为了又一个新的重要课题.ZnO纳米微晶有两种结构可以产生随机激光,一是六角柱形蜂窝状微晶结构,二是颗粒粉末状结构,产生的近紫外激光波长是387.5 nm,光泵浦阈值是50 kW/cm2.采用气相输运的催化外延晶体生长过程来制备ZnO纳米线阵列构成的光致纳米激光器,激光波长383 nm,线宽仅为0.3 nm,光泵浦阈值是40 kW/cm2. 相似文献
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用一种新颖的制备纳米粒子与薄膜的垂直靶向脉冲激光沉积(VTPLD)方法,在室温及空气气氛下,于玻璃基底上成功地制备出ZnO纳米薄膜.用扫描电子显微镜(SEM)和X射线衍射(XRD)仪对ZnO纳米薄膜的表面形貌和结构进行了表征,用荧光光谱仪对薄膜的光致发光(PL)性能进行了测量.结果表明,当激光功率为13 W时,沉积出的粒子大小较均匀,尺寸在40 nm左右,且粒子排列呈现出一定方向性;当激光功率为21 W时,沉积的ZnO纳米薄膜图呈现出微纳米孔的连续薄膜.在玻璃基底上沉积的ZnO纳米薄膜有一主峰对应的(002)衍射晶面,表明ZnO纳米薄膜具有良好的c轴取向性.不同激光功率下沉积ZnO纳米薄膜经500 ℃热处理后的PL峰,其强度随激光能量而变化,最大发光波长位于412 nm. 相似文献
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High quality zinc oxide (ZnO) micro/nano nails were prepared through thermal evaporation on the Si (100) substrate. Scanning electron microscopy (SEM) image shows that the bottom of the nanometer nails present hexagonal structure. The tip diameter of the micro/nano nails is about 319.9 nm, and the length is over 20 μm. X-ray crystal diffraction (XRD) pattern shows that the sample has a hexagonal wurtzite structure and preferred orientation in (002) direction obviously. Photoluminescence (PL) spectrum shows a strong ultraviolet (UV) luminescence peak near the wavelength of 346 nm. Finally, the growth mechanism of the ZnO micro/nano nails is analyzed and studied. 相似文献
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FU Jing XU Zheng 《中国电子科技》2003,1(1)
This paper reviews the history of ZnO varistor,discribes its properties and recenttechnological status and forecasts its evolution.The future development trend is to produce the low-voltage high-energy multi-layer ZnO varistors.After the two additives are classified by their functions,the effect mechanism of Bi_2O_3 and TiO_2 additives are researched theoretically.TiO_2 will make ZnO graingrow bigger and V_ImA/mm be depressed down.Especially the colloid TiO_2 additive in the scale ofnanometer brings about a new method to realize the low voltage of ZnO varistor,which resolves theproblem of how to disturb nanometer powder evenly.Moreover the sintering temperature has prominenteffect on the electrical properties of ZnO varistors.Generally,the appropriate sintering temperature forlow-voltage ZnO varistor ceramics should not be more than 1 250℃.These provide an effective methodand rationale for studying low-voltage ZnO varistors. 相似文献
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This paper reviews the history of ZnO varistor, discribes its properties and recent technological status and forecasts its evolution. The future development trend is to produce the low-voltage high-energy multi-layer ZnO varistors. After the two additives are classified by their functions, the effect mechanism of Bi2O3 and TiO2 additives are researched theoretically. TiO2 will make ZnO grain grow bigger and V1mA/mm be depressed down. Especially the colloid TiO2 additive in the scale of nanometer brings about a new method to realize the low voltage of ZnO varistor, which resolves the problem of how to disturb nanometer powder evenly. Moreover the sintering temperature has prominent effect on the electrical properties of ZnO varistors. Generally, the appropriate sintering temperature for low-voltage ZnO varistor ceramics should not be more than 1 250℃. These provide an effective method and rationale for studying low-voltage ZnO varistors. 相似文献
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锥状ZnO纳米结构薄膜的制备及其场发射特性 总被引:1,自引:1,他引:0
以醋酸锌和氨水为原料,采用直接水热法制备锥形纳米ZnO。借助于XRD、SEM等测试手段,对锥状纳米ZnO薄膜的制备条件、场发射特性和稳定性进行分析研究。研究结果表明,水热法直接合成的锥状纳米ZnO具有良好的场发射特性,是场发射平板显示器阴极的理想材料。 相似文献
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ZnO/Ag/ZnO多层膜的制备和性质研究 总被引:2,自引:0,他引:2
采用射频磁控溅射ZnO陶瓷靶和直流磁控溅射Ag靶的方法制备了ZnO/Ag/ZnO多层膜。用X射线衍射仪、紫外–可见分光光度计、四探针测试仪和金相显微镜对ZnO/Ag/ZnO薄膜的结构、光学透过率、方阻和稳定性进行了研究。结果表明,ZnO(60nm)/Ag/(10nm)/ZnO(60nm)薄膜呈现多晶结构,薄膜在520nm处的光学透过率高达87.5%,方阻Rs为6.2Ω/□。随着顶层ZnO薄膜厚度的增加,ZnO/Ag/ZnO薄膜的稳定性提高。 相似文献
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采用射频磁控溅射ZnO陶瓷靶、直流磁控溅射Ag靶的方法制备了不同厚度Ag夹层的ZnO(60nm)/Ag/ZnO(60nm)多层膜.分别用X射线衍射仪、紫外可见分光光度计、四探针测试仪对样品的结构、光学性质、电学性质进行了研究.结果表明:随着Ag层厚度的增加,ZnO/Ag/ZnO多层膜呈现多晶结构,Ag(111)衍射峰的强度增强.Ag夹层厚度为11nm时,ZnO(60nm)/Ag/ZnO(60nm)膜在554nm处的透过率高达92.3%.随着Ag层厚度的增加,Ag膜的特征吸收峰呈现红移和宽化,ZnO/Ag/ZnO多层膜的面电阻先减小后趋于稳定. 相似文献