Fundamental Absorption Edge of Thin PbWO4 Films

Based on the temperature dependence of the fundamental absorption edge of thin PbWO₄ films, we studied the exciton–phonon interaction, which made it possible to interpret the absorption edge as the absorption of autolocalized excitons. The temperature dependence of the forbidden band gap is investigated.     

Zinc Oxide Thin Films for Memristive Devices: A Review

Zinc Oxide (ZnO) thin films have been addressed as promising candidates for the fabrication of Resistive Random Access Memory devices, which are alternative to conventional charge-based flash memories. According to the filamentary conducting model and charge trapping/detrapping theory developed in the last decade, the memristive behavior of ZnO thin films is explained in terms of conducting filaments formed by metallic ions and/or oxygen vacancies, and their breaking through electrochemical redox reactions and/or recombination of oxygen vacancies/ions. A comparative review of the memristive properties of ZnO thin films grown by sputtering, atomic layer deposition (ALD), pulsed laser deposition (PLD), and sol-gel methods is here proposed. Sputtered ZnO thin films show promising resistive switching behaviors, showing high on/off ratios (10–10⁴), good endurance, and low operating voltages. ALD is also indicated to be useful for growing conformal ZnO layers with atomic thickness control, resulting in important resistive switching characteristics, such as relatively high on/off ratios and low operating voltages. High insulating epitaxial ZnO thin films can be obtained by PLD, showing reliable switching properties at low voltages and with good retention. On the contrary, the sol-gel approach generally results in ZnO thin films with poor resistive switching behaviors. Nevertheless, thin films derived from ZnO NPs show improved switching performances, with higher on/off ratios and lower operating voltages. Independently of the synthetic approach, doped ZnO thin films exhibit better resistive switching behaviors than pristine ones, coupling a strong increase of the on/off ratio with a more stable switching response.     

衬底温度对氧化锌薄膜电学性质的影响

氧化锌是一种性能良好的半导体材料,可以用作薄膜场发射阴极中的电子传输层材料,主要研究了用磁控溅射方法在不同衬底温度下生长ZnO薄膜的电学特性,分析了ZnO薄膜的电阻率和击穿场强随温度的变化关系。     

用等离子体辅助分子束外延生长氧化锌单晶薄膜

利用等离子体辅助分子束外延(P-MBE)方法,通过优化生长条件,在c平面蓝宝石(Al_2O_3)上生长出氧化锌(ZnO)单晶薄膜。使用反射式高能衍射仪(RHEED)原位监测到样品表面十分平整,X射线摇摆曲线(XRC)测得ZnO薄膜的<002>取向半峰全宽为0.20°,证实为ZnO单晶薄膜。室温下吸收谱(ABS)和光致发光(PL)谱显示了较强的激子吸收和发射,且无深能级(DL)发光。电学性能测量表明,生长的ZnO为n型半导体,室温下载流于浓度为7×10~(16) cm~(-3),与体单晶ZnO中的载流子浓度相当。     

Optical and Electrophysical Properties of Thin Zinc Oxide Films Doped with Manganese Oxide and Obtained by Laser Deposition

Journal of Applied Spectroscopy - Nanostructured thin films on a silicon substrate were obtained on a ceramic of zinc oxide doped with manganese oxide by high-frequency periodic pulsed laser action...     

X-Ray Luminescence of Zinc Oxide Thick Films

Optics and Spectroscopy - Samples of thick (about 30 μm) films of undoped zinc oxide on sapphire prepared by magnetron sputtering using an uncooled target have been investigated. The...     

ZnO及其含锌混合氧化物薄膜的充放电性能研究

从充放电性能、晶体结构等方面考察了包括粉末状的ＺｎＯ、脉冲激光沉积方法制备的ＺｎＯ薄膜和含锌混合氧化物薄膜的电化学性质。结果表明,ＺｎＯ粉末制备的电极 的嵌入容量随退火温度的升高而增大,掺他氧化物可以明显改善ＺｎＯ薄膜的电化学性能,在Ａｒ气氛中,基片温度为４００℃时,沉积的靶子成分为Ｚｎ：Ｂ：Ｐ：Ａｌ＝１：１：０．５：０．５（摩尔比）的含锌混合氧化物薄膜具有较高的可逆容量,且循环性能良好。     

钒氧化物薄膜的拉曼散射

用射频磁控溅射以纯金属钒做靶材在氩氧混合气体中制备了钒氧化物 (VO2 (B)、V6O1 3、V2 O5)薄膜。报导了钒氧化物薄膜的拉曼光谱 ,结合这些钒氧化物不同的结构特点 ,对它们的拉曼光谱进行了分类讨论     

Second Harmonic Generation in Thin Zinc Sulfide Films

Optical second harmonic generation, mechanical stresses, and structure are investigated in thin polycrystalline zinc sulfide films. The resulting data indicate that there is no correlation between the mechanical stresses and the quadratic optical nonlinearity. In view of the X-ray diffraction results, the nature of the nonlinearity is explained using the model of a nanotextured film consisting of crystallites with the sphalerite or wurtzite structure. It is shown that this model allows satisfactory agreement between calculations and experiment.     

利用P-MBE方法在(400)Si衬底上生长ZnO薄膜

利用等离子体辅助分子束外延(P-MBE)方法在(400)Si衬底上生长ZnO薄膜。为改善生长后样品的质量,把样品解理成三块后,在不同温度下氧气气氛中退火。通过X射线衍射(XRD)谱和光致发光(PL)谱进行表征,讨论了用P-MBE方法在Si基上生长的ZnO的室温光致发光发光峰的可能原因。     

溶剂对溶胶-凝胶法制备的掺铝氧化锌透明导电薄膜性质的影响

采用溶胶-凝胶法在玻璃基底上制备得到了高透光率,高导电性的掺铝氧化锌薄膜。研究了溶剂对薄膜晶体结构,薄膜厚度,表面形貌,光学性质和电学性质的影响,结果表明:在相同的制备条件下,薄膜的厚度随溶剂沸点的升高而降低;低沸点溶剂制备的薄膜由c轴择优取向的六角纤锌矿结构的晶体构成,且比较致密;所有薄膜可见光区的透光率在85%以上;乙二醇独甲醚为溶剂制备的薄膜电阻率最低,为3.0×1-0 4Ωm。     

Nonlinear Absorption Properties of nc-Si:H Thin Films

It is reported in this paper that the phenomenon of the saturated absorption of the exciton in hydrogenated nanocrystalline silicon (nc-Si:H) thin film fabricated by plasma enhanced chemical vapor deposition (PECVD) without any post-processing is observed at room temperature using pump-probe technology. This nonlinear optical absorption property is induced by the surface effect of the silicon nanoparticles in nc-Si:H thin films.     

Room Temperature Bolometric Applications Using Manganese Oxide Thin Films

We report the optical responses of magnetic manganese oxide La_2/3Ca_1/3MnO thin films at room temperature. The voltage responses to a He-Ne laser at the wavelength of 0.63 m and incident infrared (IR) power at the wavelength of 8-14 m were measured. The measured signals were attributably to a bolometric response due to the heating of the sample by radiation. We report the optical responses in La_2/3Ca_1/3MnO thin films as a function of chopping frequency and bias current. The noise behavior around room temperature was also discussed. It is suggested that perovskite manganese oxide thin films are suitable candidates for uncooled optical detectors.     

铜掺杂氧化锌薄膜阻变特性的研究

以 ZnO：Al为底电极,Cu为顶电极,在同种工艺条件下分别制备了类电容结构的纯ZnO 阻变器件和ZnO：2%Cu阻变器件,分析比较了两种器件的典型I-V特性曲线、置位电压（V_Set）和复位电压（V_Reset）的分布范围、器件的耐久性。结果显示,ZnO：Cu阻变器件较纯ZnO阻变器件有更大的开关比和更稳定的循环性能。另外,研究了 ZnO：Cu阻变器件的阻变机理,通过对其I-V特性曲线分析得出以下结论：ZnO：Cu阻变器件在高阻态遵循空间电荷限制电流效应,低阻态符合欧姆定律。     

偶氮金属螯合物薄膜的光学常数和吸收光谱

偶氮金属螯合物薄膜是一类新型光信息存储和光学非线性材料。通过旋涂法在单晶硅上制备了三种新型偶氮染料：2-（4-甲革-2-噻唑基偶氮）-5-二乙基胺苯酚（MTADP）掺杂聚合物,MTADP的镍螯合物（Ni-MTADP）和锌螯合物（Zn-MTADP）薄膜。利用宽谱扫描全自动椭圆偏振光谱仪测定了上述薄膜的椭偏光谱,获得了三种薄膜在400—700nm波段的复折射率、复介电常量和吸收系数。两种金属螯合物薄膜的共振波长比非螯合物薄膜红移了60—70nm;光学常数和吸收系数在峰值的数值也发生了明显的变化。由于这两种螯合物具有不同的立体结构,Ni-MTADP薄膜的共振波长比Zn-MTADP有10nm的红移。     

Er2O3薄膜的光学常数和介电性能

采用射频磁控反应溅射技术,在不同的Ar/O2流量比条件下制备了系列Er2O3薄膜样品.采用椭偏光谱和紫外一可见光透射光谱测试分析技术,研究了Er2O3薄膜的折射率、消光系数、透射率和光学带隙等光学常数与制备工艺的关系.研究了不同条件下制备的Er2O3薄膜的介电常数和Ⅰ～Ⅴ特性.结果表明,Er2O3薄膜的折射率、禁带宽度和介电常数随Ar/O2流鼍比的增加而增加,而消光系数基本不随Ar:O2流量比的变化而变化.在Ar:O2流量比为7:1制备的Er2O3薄膜具有较好的物理性能,在可见红外波段其折射率约1.81,消光系数为3.7×10-6,禁带宽度5.73 eV,介电常数为10.5.     

纳米结构氧化薄膜的固态多核核磁共振研究(英文)

Knowledge of the structure of thin oxide films is very important for electrochemistry, microelectronics and catalyses. Supported oxide catalysts （supported thin oxide films） are used extensively in the petroleum, chemical and pollution control industries as catalysts for a wide range of chemically important transformations.     

Crystallization of Poly(Ethylene Oxide) in Thin Films

Crystallization of poly(ethylene oxide) (PEO) in thin films was studied using hot-stage polarized optical microscopy. Isothermal linear crystal growth rates were measured for various film thicknesses at various degrees of undercooling. At a given crystallization temperature, the linear crystal growth rate decreased exponentially with decreasing film thickness below a film thickness of 80 nm. Films showed similar spherulitic morphology down to a film thickness of 30 nm. Control experiments on hydrophilic and hydrophobic surfaces showed that surface chemistry affects stability of the polymer films and causes a competition between crystallization and dewetting.