Na+掺杂ZnO薄膜的结构和电学性能

以醋酸锌为溶质、碳酸钠为钠源,采用溶胶-凝胶法在Si〈100〉衬底上制备了钠掺杂ZnO薄膜,掺杂浓度分别为0,0.018,0.036,0.045,0.063和0.09 mol/L.研究了钠掺杂后ZnO晶胞尺寸和表面形貌的变化规律,用霍尔效应仪测试了试样的载流子浓度及导电类型,分析了材料的拉曼光谱与试样内部缺陷浓度的关系.结果表明:Na 离子可进入ZnO晶格取代Zn2 ,导致晶胞变大,同时ZnO薄膜由n-型转变为p-型导电;当Na 掺杂浓度达0.045 mol/L时,其电阻率为75.7Ω·cm,空穴浓度2.955×1017 /cm3.     

超声波探头位置对Al-5.7%Cu铸锭凝固组织的影响

研究了超声波探头位置变化对Al-5.7%Cu合金铸锭凝固组织的影响,考察了探头水平位置变化对等轴晶占有率的影响,探讨了超声波作用下晶粒细化机理。结果表明:当探头浸入深度相同且位于铸型中心线时,得到的细等轴晶区最大,且呈对称分布;当探头的位置贴近铸型壁时,细等轴晶区向探头端面附近集中并缩减,柱状晶区进一步扩大。超声波的细化效果来自于声空化造成微区瞬时过冷,以及动态形核;而声流造成凝固的枝晶破碎,提供结晶核心。     

基于高频等离子体熔融技术制备镱铝共掺石英玻璃

利用高频等离子体粉末熔融技术成功制备出镱铝共掺石英玻璃,并对其相关机理和工艺进行研究,解决了镱铝共掺石英玻璃熔点高、难以制备的难题。该技术为拉制大尺寸和多芯掺杂光子晶体光纤提供可能,并可实现多种稀土离子单掺或共掺。通过采用辅助加热和在氧气气氛下熔融,实现了镱铝共掺石英玻璃内气泡的排除,抑制了镱离子的还原。以此玻璃为纤芯利用堆积-拉丝技术拉制的镱铝共掺光子晶体光纤在1200nm波长处的背景损耗值小于0.25dB/m,并且以此光纤为增益介质搭建的激光系统得到了激光输出。测试结果表明该技术制备的镱铝共掺石英玻璃具有非常好的光学特性。     

The investigation of electrodeposited Cu2O/ITO layers by chronocoulometry process: effect of electrical potential

The thin films of Cu₂O are deposited by electrodeposition technique onto indium tin oxide (ITO)-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M of CuSO₄ and citric acid at kept temperature of 60℃ and the applied potential varies within the {-0.4 V,-0.7 V} SCE range. Based on the chronocoulometry (CC) process, the electrochemical, structural and optical parameters are determined. We measured the current as function of potential within the {-0.4 V,-0.7 V} range and the higher current is found to be within the {-0.7 V,-0.3 V} band. The grain sizes are of 12.12 nm and 35.47 nm according to (110) and (221) orientations respectively. The high textural coefficient of 0.943 is recorded for the potential-0.7 V. The transmittance of 72.25 %, within the visible band, is obtained for the as-grown layer at-0.4 V and the band gap is found to be 2.2 eV for the electrodeposition potential of-0.7 V.     

PbS/Cu2O异质结的制备和性能表征

采用电化学沉积法在酸性电解液中制备n型Cu2O薄膜,并对其进行Cl掺杂,制备Cu2O-Cl结构.然后利用连续离子吸附法在样品薄膜上复合PbS量子点.通过SEM和UV-vis对样品进行表征,并对样品的光电化学性能进行了测试.结果表明,未掺杂的Cu2O对PbS量子点的吸附能力较强一些,经PbS敏化后的样品在太阳光谱的吸收拓展到了近红外区,PbS/Cu2O和PbS/Cu2O-Cl复合结构的光电化学性能均有所增加,尤其是短路电流密度.PbS复合后的样品转换效率最高仅为0.67％,主要原因是两者能级的不匹配,形成异质结时引入界面态,得不到理想的转换效率.     

稀土Dy掺杂ZnTe薄膜光学性能及其XPS研究

本文采用真空蒸发法,在玻璃衬底上制备了稀土元素Dy掺杂的ZnTe薄膜。利用X射线衍射仪、原子力显微镜、紫外-可见分光光度计、XPS对薄膜的物相结构、表面形貌、光学特性、元素成分等进行了测试。XRD测试结果表明,薄膜的结构均为立方晶系闪锌矿结构,择优取向为(111)晶面,Dy掺杂会使(111)峰强减弱;透射光谱表明Dy掺杂会使薄膜的光学带隙减小;XPS分析表明,薄膜的主要成分为ZnTe,掺杂后Zn和Te的特征峰均向高能端发生移动。。     

Electrochemical characteristics of phosphorus doped Si-C composite for anode active material of lithium secondary batteries

Phosphorus doped silicon-carbon composite particles were synthesized through a DC arc plasma torch. Silane(SiH₄) and methane(CH₄) were introduced into the reaction chamber as the precursor of silicon and carbon, respectively. Phosphine(PH₃) was used as a phosphorus dopant gas. Characterization of synthesized particles were carried out by scanning electron microscopy(SEM), X-ray diffractometry(XRD), X-ray photoelectron spectroscopy(XPS) and bulk resistivity measurement. Electrochemical properties were investigated by cyclic test and electrochemical voltage spectroscopy(EVS). In the experimental range, phosphorus doped silicon-carbon composite electrode exhibits enhanced cycle performance than intrinsic silicon and phosphorus doped silicon. It can be explained that incorporation of carbon into silicon acts as a buffer matrix and phosphorus doping plays an important role to enhance the conductivity of the electrode, which leads to the improvement of the cycle performance of the cell.     

锶元素改性TiO2／杭锦2#土复合物的光催化性能

以Ti（OBu）4和内蒙古杭锦2^#土为主要原料，Sr（NO3）2为掺杂剂，采用溶胶-凝胶法制备了一系列Sr元素掺杂改性的TiO2／杭锦2^#土复合光催化剂，并用X射线衍射、傅立叶红外光谱和扫描电子显微镜等对样品进行了表征。紫外光照射下，以亚甲基蓝水溶液为光降解体系，考察了Sr的掺杂量和热处理温度对光降解率的影响，结果表明，Sr的掺杂量为0．5％，焙烧温度为500℃条件下制得复合物的催化活性明显优于相同条件下的TiO2／杭锦2^#土。该复合物催化剂的优点是易于从分散体系中分离和可循环使用。     

氮掺杂TiO2/AC催化剂光降解CEH漂白废水

以酸催化水解法制得的活性炭(AC)负载N掺杂TiO2 (TON/AC)为光催化剂,在太阳光照射下对实际CEH漂白废水进行了光催化处理,并以COD为评价指标,考察了催化剂用量、太阳光催化降解时间、废水pH、催化剂利用次数等指标的影响.结果表明,此法制备的TON/AC光催化剂具有较高的太阳光催化活性,且可多次循环使用;在TON/AC用量为1.0 g/L、初始pH值为3.0的条件下,经太阳光催化降解8 d后,对CEH漂白废水中COD的去除率可达73.35%.     

用装有藻类衍生石花菜的密实塔从工业废水中去除铜和铬

Vitor J．P．Vilar，等采用琼脂生产厂生产琼脂的藻类废料——藻类石花菜研究了从工业废水中去除Cu（Ⅱ）和Cr（Ⅲ）的可行性。涉及的废液有含Cu（Ⅱ）废液及含Cu（Ⅱ）废液与含Cr（Ⅳ）废液的混合液，Cr（Ⅵ）预先被还原成Cr（Ⅲ）。对于含Cu（Ⅱ）溶液，用藻类石花菜和2种复合材料进行了3个循环的连续吸附（Cu（Ⅱ）质量浓度约50mg／L）-解吸（0．1mol／LHNO3）试验。生物群的吸附能力几乎保持恒定，接近于从纯Cu（Ⅱ）溶液中吸附的量，表明生物群的寿命足以满足工业过程。