射频磁控溅射法制备GZO:Ti薄膜的微结构及其光学性质

采用射频(RF)磁控溅射工艺于玻璃衬底沉积了镓钛 共掺杂氧化锌(GZO:Ti)半导体薄膜,研究了沉积 温度对薄膜微观结构和光学性质的影响。通过X射线衍射仪(XRD)和紫外分光光度计对其晶体 结构和透射光谱特 性进行表征,同时利用光谱拟合法获取了薄膜的光学常数。研究结果表明,所有薄膜均具备 六角纤锌矿结 构和c轴择优取向特性,沉积温度对薄膜的微结构参数、光学 常数和光学带隙具有明显调控作用,当沉积 温度为653K时,GZO:Ti薄膜的晶粒尺寸最大(82.12nm)、位错密度最低(1.48×10－4 nm－2) 、微应变最小(0.001)、可见光区平均透射 率 最高(82.06%)及光学带隙值最大(3.57eV )。     

Cellulose‐Based Ionogels for Paper Electronics

A new class of biofriendly ionogels produced by gelation of microcellulose thin films with tailored 1‐ethyl‐3‐methylimidazolium methylphosphonate ionic liquids are demonstrated. The cellulose ionogels show promising properties for application in flexible electronics, such as transparency, flexibility, transferability, and high specific capacitances of 5 to 15 μF cm^?2. They can be laminated onto any substrate such as multilayer‐coated paper and act as high capacitance dielectrics for inorganic (spray‐coated ZnO and colloidal ZnO nanorods) and organic (poly[3‐hexylthiophene], P3HT) electrolyte‐gated field‐effect transistors (FETs), that operate at very low voltages (<2 V). Field‐effect mobilities in ionogel‐gated spray‐coated ZnO FETs reach 75 cm² V^?1 s^?1 and a typical increase of mobility with decreasing specific capacitance of the ionogel is observed. Solution‐processed, colloidal ZnO nanorods and laminated cellulose ionogels enable the fabrication of the first electrolyte‐gated, flexible circuits on paper, which operate at bending radii down to 1.1 mm.     

Development of dry processing techniques for CdZnTe surface passivation

A method for passivating the surface of Cd_1−xZn_xTe (CZT) x-ray and gamma ray detectors using relatively simple dry processing techniques has been developed. Leakage currents were significantly reduced for several processing methods. CZT samples were exposed to an oxygen plasma and/or coated with a reactively sputtered silicon nitride layer. Several parameters of the oxygen plasma step were found to be important for achieving enhanced surface resistivity. SiN_X has been previously characterized and was used because of its high dielectric quality and low deposition temperature. Reduction in leakage current after passivation by a factor of as much as twenty is demonstrated. Results are also presented which give a measure of the long-term stability of the passivating layers.     

Nanocomposite Microcontainers with High Ultrasound Sensitivity

A water suspension of nanocomposite microcapsules with embedded ZnO nanoparticles in the capsule shell is reported. The microcapsule morphology is characterized by confocal microscopy, TEM, SEM, and AFM before and after ultrasound treatment. A remarkably high capsule sensitivity to ultrasound is evidenced, and it is observed to grow with increasing number of ZnO nanoparticle layers in the nanocomposite shell. This effect is correlated with the mechanical properties of microcapsules measured with AFM.     

Metallic Cobalt Nanoparticles Encapsulated in Nitrogen‐Enriched Graphene Shells: Its Bifunctional Electrocatalysis and Application in Zinc–Air Batteries

There has been a continuous call for active, durable, and low‐cost electrocatalysts for a range of energy applications. Among many different nonprecious metal based candidates, transition metal nanoparticles encapsulated in graphene layers have gained increasing attention over recent years. In this study, it is demonstrated that metallic cobalt nanoparticles sheathed by multilayered nitrogen‐enriched graphene shells can be facilely prepared using cobalt‐containing Prussian blue colloids as the single precursor. These metallic cobalt cores can be readily leached out by HCl treatment, resulting in hollow graphene spheres. Products with or without acid leaching exhibit great bifunctional activities for electrocatalytic oxygen reduction and hydrogen evolution in both alkaline and acidic electrolytes. Most importantly, it is found that the removal of the metallic cores does not deteriorate but rather enhances the electrocatalytic performance. Based on this and other experimental observations, Co‐N‐C moieties are proposed as the catalytically active sites. At last, it is shown that these catalysts can be employed as the air catalyst of primary zinc–air batteries with excellent current density, power density, and operation durability.     

正戊烷与甲醇制芳烃工艺条件的优化

以负载ZnO的ZSM-5为催化剂,利用固定床微型反应装置系统地考察了反应温度、反应空速、投料摩尔比对甲醇与正戊烷共芳构化反应的影响。结果表明：与单独芳构化相比,正戊烷与甲醇共芳构化可提高芳烃的选择性,抑制干气的生成;随着甲醇与正戊烷摩尔比的增大,正戊烷的转化率下降;正戊烷与甲醇在ZSM-5分子筛上进行芳构化反应的适宜反应条件为：温度475℃,烃基质量空速2 h^-1,甲醇与正戊烷摩尔比3∶1;在优化工艺条件下,正戊烷与甲醇共芳构化反应中芳烃的选择性可达31.68%。     

High Performance Flexible Actuator of Urchin‐Like ZnO Nanostructure/Polyvinylenefluoride Hybrid Thin Film with Graphene Electrodes for Acoustic Generator and Analyzer

A bass frequency response enhanced flexible polyvinylidene fluoride (PVDF) based thin film acoustic actuator is successfully fabricated. High concentrations of various zinc oxide (ZnO) is embedded in PVDF matrix, enhancing the β phase content and the dielectric property of the composite thin film. ZnO acts as a nucleation agent for the crystallization of PVDF. A chemical vapor deposition grown graphene is used as electrodes, enabling high electron mobility for the distortion free acoustic signals. The frequency response of the fabricated acoustic actuator is studied as a function of the film thickness and filler content. The optimized film has a thickness of 80 μm with 30 wt% filler content and shows 72% and 42% frequency response enhancement in bass and midrange compared to the commercial PVDF, respectively. Also, the total harmonic distortion decreases to 82% and 74% in the bass and midrange regions, respectively. Furthermore, the composite film shows a promising potential for microphone applications. Most of all, it is demonstrated that acoustic actuator performance is strongly influenced by degree of PVDF crystalline.     

铌酸锌系微波介质陶瓷的研究进展

介绍了微波介质陶瓷改性研究的3种常见方法,即添加助烧剂、离子取代和陶瓷复合化,综述了近几年来铌酸锌系微波介质陶瓷的研究进展.探讨了铌酸锌系微波介质陶瓷研究中存在的问题和未来的发展趋势.