常温一氧化碳气敏元件制备及气敏机理研究

介绍了以SnO2 为主 ,掺入Al2 O3 ,MgO ,InO ,Pd等添加剂的常温CO气敏元件的制备方法。根据其晶体结构特点对气敏机理进行了探讨。论述了传感器的信息传感机制 ,即晶界势垒控制和晶粒大小控制机制同时存在。为获得性能良好的气敏元件 ,需要最佳的制备方法和最好的添加剂     

超细铜粉的化学镀锡及其抗氧化性能研究

以水合肼还原法制备出平均粒径约1μm的超细铜粉,并对其进行化学镀锡。研究了镀锡层对复合粉末微观形貌及抗氧化性能的影响。结果表明:镀覆质量分数50%的锡后,复合粉末平均粒径有所减小,但在空气中的氧化起始温度从120℃提高到220℃,与镀银层相比,镀锡层在较低温度区间对铜粉抗氧化具有优势。     

Effect of deposition conditions on the physical properties of SnxSy thin films prepared by the spray pyrolysis technique

Tin sulfide thin films (Sn_xS_y) with an atomic ratio of y/x = 0.5 have been deposited on a glass substrate by spray pyrolysis. The effects of deposition parameters, such as spray solution rate (R), substrate temperature (T_s) and film thickness (t), on the structural, optical, thermo-electrical and photoconductivity related properties of the films have been studied. The precursor solution was prepared by dissolving tin chloride (SnCl₄, 5H₂O) and thiourea in propanol, and Sn_xS_y thin film was prepared with a mole ratio of y/x = 0.5. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectroscopy. It is indicated that the XRD patterns of Sn_xS_x films have amorphous and polycrystalline structures and the size of the grains has been changed from 7 to 16 nm. The optical gap of Sn_xS_x thin films is determined to be about 2.41 to 3.08 eV by a plot of the variation of (αhν)² versus hν related to the change of deposition conditions. The thermoelectric and photo-conductivity measurement results for the films show that these properties are depend considerably on the deposition parameters.     

直流磁控溅射ITO薄膜的正交试验分析

利用直流磁控溅射系统制备ITO薄膜,采用正交试验表格L32(48)安排试验.测试了薄膜的方阻和透过率,分析了8个工艺参数对薄膜电光特性的影响,其中沉积气压、氩氧流量比和退火温度的影响最大.分析得到优化工艺参数为:沉积气压2×133.322 4 mPa、氩氧流量比16∶0.5、退火温度427 ℃、靶基间距15、退火时间1 h、溅射功率300 W、退火氛围为真空、沉积温度227 ℃.在此工艺参数下制备的ITO薄膜方阻为17 Ω/□,电阻率为1.87×10-4Ω·cm,在可见光区域平均透过率为85.13%.     

(Cd,Co,Nb)掺杂的SnO2压敏材料的电学性质

研究了Cd对(Co，Nb)掺杂SnO2压敏材料电学性质的影响。组分为97．65％SnO2 O．75％Co2O3 0．10％Nb2O5 1．50％CdO的压敏电阻具有最大非线性系数(a=22．2)和最高的势垒(ψB=0．761eV)．当CdO的摩尔分数从0增加到3％时，(Co，Nb)掺杂SnO2压敏电阻的击穿电压从366V／mm增大到556V／mm，1kHz时的相对介电常数从1429减小到1108。晶界势垒高度测量揭示，SnO2的晶粒尺寸的减小是击穿电压增高和介电常数减小的主要原因。对Cd掺杂量增加引起SnO2晶粒减小的根源进行了解释。     

Electrical and optical properties of deep ultraviolet transparent conductive Ga2O3/ITO films by magnetron sputtering

Ga2O3/ITO films were prepared by magnetron sputtering on quartz glass substrates. The transmittance and sheet resistance of ITO films and Ga2O3/ITO films were measured by using a double beam spectrophotometer and four point probes. The effect of the ITO layer and Ga2O3 layer thickness on the electrical and optical properties of Ga2O3/ITO bi-layer films were investigated in detail. Ga2O3 (50 nm)/ITO (23 nm) films exhibited a low sheet resistance of 323 Ω/□ and high deep ultraviolet transmittance of 77.6% at a wavelength of 280 nm. The ITO layer controls the ultraviolet transmittance and sheet resistance of Ga2O3/ITO films. The Ga2O3 layer thickness has a marked effect on the transmission spectral shape of Ga2O3/ITO films in the violet spectral region.     

钢中铈与锡相互作用的研究

 采用中频真空感应熔炼炉、X射线衍射仪、金相显微镜、电子探针、显微硬度计等实验分析方法,研究了稀土金属铈与低熔点金属锡在钢中的相互作用。结果表明,钢液中铈和锡浓度均较高的条件下,铸态试样中可析出化合物Ce3Sn7相,沿晶界分布。经奥氏体区高温退火处理,钢中的Ce3Sn7相化合为三元FeCe3Sn6相。退火状态下FeCe3Sn6相的显微硬度大于基体的显微硬度。FeCe3Sn6相在干燥器内稳定,在纯净水和酸性水溶液中不稳定。     

空气－氢气火焰原子吸收光谱法测定重整催化剂中低含量锡

提出用原子吸收光谱测定锡的新方法。使用空气－氧气火焰比用空气－乙炔火焰测锡的灵敏度提高了６倍，检测限达０．２３４μｇ／ｍｌ。考察了４种无机酸和２２种金属离子的干扰情况，试验表明加入三氯化铁可以消除多数金属离子的干扰。平行测定８份试样的相对标准偏差为１．８３％，分析结果用三种不同的分析方法进行了验证。本文为低含量锡的测定提供了新方法。     

新型红光LED中ITO的特性研究

用真空电子束蒸镀的方法制备半导体发光二极管LED 所用的ITO(indium tin oxide)膜。利用TLM(transmission line model)研究ITO与GaP接触特性。在氮气环境,435℃条件下,快速热退火40s能获得最小的接触电阻4.3×10-3Ωcm2。Hall测试和俄偈电子能谱表明,影响接触电阻的主要原因是ITO载流子浓度的改变和In,Ga,O的扩散。另外,制作了以300nm ITO为窗口层的新型AlGaInP红光LED并研究其可靠性。发现ITO的退化导致了LED的电压持续升高。而ITO与GaP热膨胀系数的不同导致了LED的最终失效。