Development and characterization of fluorine tin oxide electrodes modified with high area porous thin films containing gold nanoparticles

Different electrode materials are prepared using fluoride doped tin oxide (FTO) electrodes modified with high area porous thin films of metal oxides containing gold nanoparticles. Three different metal oxides (TiO₂, MgO and SnO₂) have been assayed to this end. The effect of the metal oxide nature and gold loading on the structure and performance of the modified electrodes was examined by Scanning Electron Microscopy, Transmission Electron Microscopy, X-Ray Diffraction (XRD), Diffuse Reflectance Spectroscopy and electrochemical techniques. XRD measurements reveal that MgO electrodes present the smallest gold nanoparticles after the sintering step however, the electrochemical response of these electrodes shows important problems of mass transport derived from the high porosity of these materials (Brunauer Emmett Teller area of 125 m²/g). The excellent sintering properties of titania nanoparticles result in robust films attached to the FTO electrodes which allow more reliable and reproducible results from an electroanalytical point of view.     

Electronic transport and optical properties of thin oxide films

In this work, we present optical characterization of films of two transparent conductive oxides (ITO: indium tin oxide and ZnO: zinc oxide) including absorption coefficient and optical gap energy. We have also investigated the transport properties of ITO and ZnO films through measurements of electrical conductivity and thermoelectric power versus temperature. These measurements enabled us to investigate conduction mechanisms for metal-nonmetal transitions. Undoped ZnO thin films show a metal-semiconductor transition at temperatures beyond 350 K. We have conducted a similar study on ITO films where we demonstrated, for the first time, the existence of a conductivity transition below 400 K, which indicates a high absolute thermoelectric power at temperatures above the transition temperature.     

方圆公司选矿工艺的改进

按照选矿专业的理论和方法,结合方圆公司选矿工艺流程和生产的实际情况,改进了选矿工艺.     

Band‐Edge Engineered Hybrid Structures for Dye‐Sensitized Solar Cells Based on SnO2 Nanowires

In this report, we show for the first time that SnO₂ nanowire based dye sensitized solar cells exhibit an open circuit voltage of 560 mV, which is 200 mV higher than that using SnO₂ nanoparticle based cells. This is attributed to the more negative flat band potential of nanowires compared to the nanoparticles as determined by open circuit photo voltage measurements made at high light intensities. The nanowires were employed in hybrid structures consisting of highly interconnected SnO₂ nanowire matrix coated with TiO₂ nanoparticles, which showed an open circuit voltage of 720 mV and an efficiency of 4.1% compared to 2.1% obtained with pure SnO₂ nanowire matrix. The electron transport time constants for SnO₂ nanowire matrix were an order of magnitude lower and the recombination time constants are about 100 times higher than that of TiO₂ nanoparticles. The higher efficiency observed for DSSCs based on hybrid structure is attributed to the band edge positions of SnO₂ relative to that of TiO₂ and faster electron transport in SnO₂ nanowires.     

PLD法制备ITO导电薄膜及其性能

为了研制可用于高温环境下进行应变测量的应变层,采用脉冲激光沉积(PLD)法在陶瓷基底上制备了氧化铟锡(ITO)薄膜.研究了PLD法中不同基底温度对ITO薄膜显微结构、电学性能以及阻温特性的影响.采用X射线衍射仪(XRD)测试了薄膜的晶体结构,通过四点探针测量法测得薄膜的薄层电阻,采用场发射扫描电子显微镜(FESEM)对...     

含锡锌铁精矿链篦机-回转窑法制备炼铁用球团矿的研究

以含锡锌复杂铁精矿(质量分数)(0.25%Sn,0.20%Zn)为对象,进行了含锡锌铁精矿制备炼铁用球团矿的研究。在分析预热、还原焙烧过程锡、锌化合物挥发行为的基础上,重点研究了链篦机预热条件和回转窑焙烧条件对预热球、成品球团矿强度及锡、锌脱除率的影响。热力学分析表明,锡、锌的挥发脱除主要发生在弱还原焙烧阶段。实验结果表明:在优化条件下,预热球抗压强度为495N/个,AC转鼓指数为3.85%,焙烧球抗压强度为2254N/个,ISO转鼓指数为96.16%;Sn和Zn的挥发率分别为70.8%和61.0%,球团矿中残余Sn和Zn的质量分数分别为0.073%和0.078%。制备的成品球团矿冶金性能良好,各项指标均满足高炉冶炼要求。     

影响SnO2纳米晶体修饰的α-Al2O3微滤膜流动电势的因素

试验研究了不同电解质溶液pH值以及其离子浓度和种类对SnO2纳米晶体修饰的α-A120,微滤膜流动电势的影响规律,结果表明,对于Nacl溶液,膜流动电势随溶液浓度的增大而降低,其等电点在4．6左右;随着溶液的pH值由3增加到10,膜流动电势由正值逐渐变为负值,而对于FeSO4,CaSO4,Na2SO4,NaCl和CaCl2溶液,当溶液的浓度固定时,膜流动电势随溶液电导率的增加而降低。     

Influence of ITO patterning on reliability of organic light emitting devices

Indium tin oxide (ITO) films are widely used for a transparent electrode of organic light emitting devices (OLEDs) because of its excellent conductivity and transparency. Two types of ITO substrates with different surface roughness were selected to use as anode of OLEDs. In addition, two types of etching process of ITO substrate, particularly the etching time, were also carried out. It was found that the surface roughness and/or the etching process of ITO substrate strongly influenced on an edge of ITO surface, further affected the operating characteristics and reliability of devices.     

Study of the inductively coupled plasma assisted DC magnetron sputtering (ICPDMS) during ITO deposition

An inductively coupled plasma (ICP) assisted DC magnetron sputtering (ICPDMS) method for the deposition of indium tin oxide (ITO) thin films was developed to satisfy the challenging requirements of a room temperature process and high temperature durability. The resistivity of ITO thin films deposited by ICPDMS at room temperature was improved to as low as 1.2 × 10^− 2 Ω cm by increasing the RF power of the ICP source to 1200 W. Due to the additional dissociation and ionization by the high density plasma in ICPDMS system, the ITO thin films have a higher portion of Sn and oxygen atoms and a lower initial carrier concentration, ~ 10¹⁸ #/cm³, at room temperature than conventional ITO. However, the carrier concentration could be rapidly increased up to 10²⁰ #/cm³ by post-annealing to temperatures as high as 500 °C for 1 h under high vacuum conditions. Unlike conventional ITO, the electrical properties of ICPDMS-ITO were relatively unchanged after high temperature heat cycles, which is a very attractive property for high performance photovoltaic solar cell applications.