SiO2溶胶及其静电自组装薄膜的制备

采用HCl催化、NH3 ·H2 O催化、HCl与NH3 ·H2 O分步催化三种途径制备了SiO2 胶体 ,用透射电镜观察了胶体粒子的形貌 .用静电自组装 (ESAM)法制备了聚电解质PDDA与SiO2 胶体粒子的有机 /无机复合光学薄膜 .实验结果表明 ,用HCl催化制备的SiO2 透明溶胶不适合于用ESAM法制备薄膜 ,用HCl与NH3 ·H2 O分步催化以及用NH3 ·H2 O单独催化制备的SiO2 胶体适合于用ESAM法制备光学薄膜 .薄膜的透射电镜微观察结果表明 ,以HCl与NH3 ·H2 O分步催化的SiO2 胶体制备的PDDA/SiO2 薄膜为连续结构 ,NH3 ·H2 O单独催化的为颗粒堆积 .研究了薄膜透光率与薄膜层数的关系 ,考察了薄膜的机械强度 .结果显示 ,以NH3 ·H2 O单独催化的SiO2 胶体制备的光学薄膜的增透效果较好 ,但耐机械擦伤强度较弱     

电致变色氧化钨薄膜锂离子阈值注入量的研究

探讨了ＷＯ３薄膜与１ＭＬｉＣｌＯ４－ＰＣ溶液之间的界面电位差的变化规律及测量方法，制备了三种具有不同电致变色性能的ＷＯ３薄膜，并对它们进行了界面电位差随Ｌｉ＾＋注入量大小变化的测量，通过实验发现，界面电位差的变化趋势能够反映出氧化钨薄膜的Ｌｉ＾＋离子阈值注入量的大小。进而找到了用电阻热蒸发方法制备了电致变色氧化钨薄膜的最佳工艺条件。     

SiO2静电自组装增透膜光学性质的研究

采用HCl与NH3@H2O分步催化制备了SiO2胶体,在同一终点pH值下可得到不同的粒度.用静电自组装法制备了PDDA/SiO2有机/无机多层复合光学增透薄膜.用TEM测试了薄膜的微观结构,用721分光光度计监测了薄膜的透射率,研究了薄膜的光学性能随薄膜层数及波长的变化.     

反应溅射法制备TiO2薄膜

报道了用反应溅射法制备TiO₂薄膜的实验研究.详细研究了氧分压、基底温度和退火温度对成膜结构的影响.制备出了具有金红石和锐钛矿晶体结构的TiO₂薄膜.分析了金红石和锐钛矿晶体的形成条件,并对薄膜的表面形貌进行了测量. 关键词： 反应溅射 2薄膜')" href="#">TiO₂薄膜     

Hg_(1-x)Cd_xTe梯度带隙薄膜材料生长及红外透射光谱研究

利用气相外延法生长了Hg1-xCdxTe梯度带隙薄膜材料,通过小光点红外透射光谱测试,研究了材料的横向组分波动.利用多层模型和膜系传递矩阵对该薄膜材料的红外透射光谱和气相外延薄膜材料的纵向组分分布进行计算,计算结果与实验吻合,材料纵向组分分布与通过能谱测量的样品截面组分变化趋势一致.用光伏器件的制作工艺,选取气相外延生长的Au掺杂中波材料,制备了10元线列器件,测试结果表明器件性能较好,95K黑体D*λP可达4.20×1011(cm·Hz1/2·W-1).     

非晶SnO2:(Cu,In)薄膜的荧光特性及带尾态

用反应蒸发法在玻璃等衬底上制备出铜和铟掺杂的氧化锡SnO2:(Cu,In)薄膜.对制备薄膜的发光性质做了研究,制备样品为非晶态,具无定形结构.测量了薄膜在220-1100 nm范围的透过率,得到的带隙宽度Eopt g=4.645 eV.室温条件下对样品进行光致发光测量,得到了显著的紫外(276-550 nm)蓝绿光连续谱,通过发光谱的研究给出了这种材料的隙态分布.     

一种获得半导体薄膜光学参数的方法

实现薄膜光学参数的简便测量对于薄膜的制备和应用具有重要意义。引入适用于半导体材料的Forouhi_Bloomer模型,用其表征薄膜折射率与色散的关系。考虑到粗糙度的影响,假设薄膜厚度服从正态分布,给出了模拟退火法与迭代法相结合、由可见光光谱测定薄膜光学参数的方法。作为尝试,以硅系薄膜为例进行了计算。结果表明,获得的厚度与用椭偏仪测量的结果较为吻合。该方法适用于研究和测量半导体薄膜的光学性能和膜厚,具有很高的实用价值。     

低真空条件下制备的银薄膜的电阻率特性及结构

研究了在2.2 Pa低真空条件下用直流溅射法制备的银薄膜的电阻率特性和薄膜结构.实验表明,薄膜厚度对薄膜电阻率有显著影响,随膜厚的增加薄膜电阻率降低,在膜厚大于200 nm时趋于稳定,电阻率为2.54×10-8Ω.m.薄膜表面和晶粒间界对传导电子的散射导致了银薄膜电阻率的尺寸效应.研究结果表明,可以在2.2 Pa的低真空条件下制备金属银薄膜,将银靶用于目前大学物理实验课中金属薄膜制备及金属薄膜电阻率测量实验是可行的.     

用磁控溅射法制备Cu薄膜的研究

采用磁控溅射法在玻璃衬底上制备了Cu薄膜 ,应用台阶仪测量Cu膜的厚度 ,研究了薄膜的沉积速率与溅射功率的关系 ;用X射线衍射 (XRD)和扫描电镜Cu对薄膜进行了表征 ,研究了溅射功率对所制备薄膜的影响。制备出致密性和均匀性较好的Cu薄膜。     

薄膜系列实验的教学研究

从薄膜制备、生长过程动态分析以及形貌表征3方面设计了薄膜系列实验.用离子束溅射制备金属薄膜,研究了制备条件对溅射速率的影响,测量了薄膜生长过程中电阻的变化,用扫描隧道显微镜或原子力显微镜观测薄膜的表面形貌,并分析不同制备条件得到的薄膜的表面形貌特征.     

Structural and optical properties of Au-implanted ZnO films

The structural and luminescence related optical behaviours of Au ion implanted ZnO films grown by magnetic sputtering and their post implantation annealing behaviours in the temperature range of 100-700 °C have been investigated. Optical absorption and transmittance spectra of the films indicate that band edge of Au-implanted ZnO has shifted to high energy range and optical band gap has increased, because the sharp difference of thermal expansion induces the lattice mismatch between ZnO and SiO₂. PL spectra reveal that UV and visible luminescence bands of ZnO films can be improved after thermal annealing due to recovery of defects and Au ions incorporation. Importantly, green luminescence band of 530 nm has been only observed in the Au-implanted and subsequently annealed ZnO films and it enhances with the increasing annealing temperature, which can be related to Au atoms or clusters in ZnO films. Furthermore, X-ray photoelectron spectroscopy measurements reveal that the Au⁰ is dominant state in Au implanted and annealed ZnO films. Possible mechanisms, such as optical transitions of Au atoms or clusters and deep level luminescence of ZnO, have been proposed for green emission.     

120keV的N+注入SiC薄膜的光谱特性研究

文中主要研究了120keV的N⁺注入后SiC薄膜样品的光致发光谱(PL)和傅立叶红外光谱(FTIR)特性.从红外光谱可以看到有明显得碳氮单键、双键、三键等新结构生成.从PL光谱则发现365nm处的发光峰明显增强,这表明N⁺注入使得带隙中深的能级辐射中心复合的效率大幅度提高     

80keV N离子注入对ZnO薄膜结构的影响

室温下用80keVN离子注入ZnO薄膜样品,注量分别为5.01014,5.01015和5.01016ions/cm2,然后用X射线衍射和透射电镜技术对样品的结构特性进行了表征。实验结果表明,由高度(002)择优取向的致密柱状晶构成的薄膜中,注入5.0×1015ions/cm2时,观测到缺陷生成和局域无序化现象,但薄膜总体结构仍保持柱状晶和(002)择优取向;随着注量的增大,晶格常数c和压应力呈增大趋势。对注入N离子对ZnO薄膜结构特性的影响机理进行了简单的讨论。     

Ag implantation-induced modification of Ni–Ti shape memory alloy thin films

Nanocrystalline thin films of Ni–Ti shape memory alloy are deposited on an Si substrate by the DC-magnetron co-sputtering technique and 120?keV Ag ions are implanted at different fluences. The thickness and composition of the pristine films are determined by Rutherford Backscattering Spectrometry (RBS). X-Ray diffraction (XRD), atomic force microscopy (AFM) and four-point probe resistivity methods have been used to study the structural, morphological and electrical transport properties. XRD analysis has revealed the existence of martensitic and austenite phases in the pristine film and also evidenced the structural changes in Ag-implanted Ni–Ti films at different fluences. AFM studies have revealed that surface roughness and grain size of Ni–Ti films have decreased with an increase in ion fluence. The modifications in the mechanical behaviour of implanted Ni–Ti films w.r.t pristine film is determined by using a Nano-indentation tester at room temperature. Higher hardness and the ratio of higher hardness (H) to elastic modulus (E_r) are observed for the film implanted at an optimized fluence of 9?×?10¹⁵ ions/cm². This improvement in mechanical behaviour could be understood in terms of grain refinement and dislocation induced by the Ag ion implantation in the Ni–Ti thin films.     

Al2O3陶瓷衬底碳离子预注入对金刚石薄膜应力的影响研究

通过对Al2O3陶瓷衬底进行碳离子预注入，大大降低了Al2O3陶瓷衬底上金刚石薄膜的应力，且金刚石薄膜中的压应力随碳离子注入剂量的增加而线性下降.通过对Al2O3陶瓷衬底注入前后的对比分析表明，高能量的碳离子注入Al2O3陶瓷衬底以后，并没有产生过渡层性质的新相，而是大量累积在Al2O3晶格的间隙位，使Al2O3晶格发生畸变.而且，随着碳离子注入剂量的增加，Al2O3基体内晶格畸变加剧，注入层残余压应力也随之上升.当金刚石薄膜沉积以后，在降温的过程中衬底这部分残余应力得到释放，从而部分弛豫了金刚石薄膜中的 关键词： 金刚石薄膜 应力 离子注入 Al2O3陶瓷     

Defect studies of hydrogen-loaded thin Nb films

Hydrogen interaction with defects in thin niobium (Nb) films was investigated using slow positron implantation spectroscopy (SPIS) combined with X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thin Nb films on Si substrates were prepared using cathode beam sputtering at room temperature. Initially, the microstructure of the virgin (hydrogen-free) films was characterized. Subsequently, the films were step-by-step electrochemically charged with hydrogen and the evolution of the microstructure with increasing hydrogen concentration was monitored. Hydrogen loading leads to a significant lattice expansion which was measured by XRD. Contrary to free-standing bulk metals, thin films are highly anisotropic. The in-plane expansion is prevented because the films are clamped on the elastically hard substrate. On the other hand, the out-of-plane expansion is substantially higher than in the bulk samples. Moreover, an enhanced hydrogen solubility in the α-phase was found in nanocrystalline Nb films. It was found that most of positrons in the films are trapped at open-volume defects at grain boundaries (GBs). These defects represent trapping sites also for hydrogen atoms. Hydrogen trapping at vacancy-like defects like GBs leads to a local increase of the electron density and is reflected by a pronounced decrease of the S parameter in the hydrogen-loaded samples. In addition, it was found that new defects are introduced at higher concentrations of hydrogen due to the formation of NbH (β-phase) particles.     

磷离子注入纳米金刚石薄膜的n型导电性能与微结构研究

系统研究了磷离子注入并在不同温度退火后的纳米金刚石薄膜的微结构和电学性能.研究表明,当退火温度达到800 ℃以上时,薄膜呈良好的n型电导.Raman光谱和电子顺磁共振谱的结果表明,薄膜中金刚石相含量越高和完整性越好,薄膜电阻率越低. 这说明纳米金刚石晶粒为薄膜提供了电导.1000 ℃退火后,薄膜晶界中的非晶石墨相有序度提高,碳悬键数量降低,薄膜电阻率升高.薄膜导电机理为磷离子注入的纳米金刚石晶粒提供了n型电导,非晶碳晶界为其电导提供了传输路径. 关键词： 纳米金刚石薄膜 n型 磷离子注入     

Deep defects generated in n-conducting ZnO:TM thin films

The ferromagnetism in highly transparent and intrinsically n-type conducting zinc oxide doped with 3d transition metals (TM), is predicted to be defect mediated. We investigate the generation of deep defects in n-conducting 1 μm thick ZnO:TM films (TM=Co, Mn, Ti) with a nominal TM content of 0.02, 0.20 and 2.00 at.% grown by pulsed laser deposition on a-plane sapphire substrates using deep level transient spectroscopy. We find that a defect level is generated, independent of the TM content, located 0.31 and 0.27 eV below the conduction band minimum of ZnO:Mn and ZnO:Ti, respectively. Different defect levels are generated in dependence on the Co content in ZnO:Co. This work shows that an optimization of defect-related ferromagnetism in n-conducting ZnO:TM thin films will only be possible if the preparation sensitive formation of deep defects is controlled in the same time.     

Donor-like defects in ZnO substrate materials and ZnO thin films

We have investigated donor-like defects in ZnO substrate material grown by three different methods, and in epitaxial ZnO thin films grown on sapphire by pulsed laser deposition. Temperature dependent Hall effect measurements yield information about dominant donors. The thermal activation energies lie in a wide range from about 20 meV to about 370 meV. Deep level transient spectroscopy is used to obtain parameters of deep donor-like defects. For that, a high-speed diode contact configuration was laid out for the epitaxial thin films in order to determine the defect parameters with high precision. The identified levels are E1, E3 and E4, though the level E4 is observed only in single crystals grown by seeded chemical vapor transport. PACS 72.10.Fk; 72.80.Ey; 73.50.-h