Effect of Annealing Temperature on Structural and Electrical Properties of Al/ZrO2/p-Si MIS Schottky Diodes

Silicon - The structural and electrical properties of Al/ZrO2/p-Si Schottky barrier diodes (SBDs) have been investigated at different annealing temperatures (300, 400, 500 and 600 °C). X-ray...     

Influence of Annealing Temperature on Structural and dc Electrical Properties of SnO2 Thin Films for Schottky Barrier Diodes

This paper reports about the influence of annealing temperature on the structural, morphological, optical and electrical properties of SnO₂ thin films prepared by the spin-coating method. The structural analysis reveals the presence of rutile SnO₂ with tetragonal structure and its defects are reduced in higher annealing temperatures. SEM images show that the size of the grains was improved due to increase in annealing temperature. From UV-visible analysis, band gap energy (E_g), refractive index (n), and extinction coefficient (k) are estimated. The band gap energy increases from 3.46 to 3.54 eV with annealing temperatures. dc analysis shows that the Arrhenius conduction mechanism has a profound influence on the electrical conductivity and varies in the range 1.08–6.80 × 10^− 8(Ω cm)^− 1 with annealing temperature. The Al/n-SnO₂/p-Si Schottky barrier diode parameters such as ideality factor (n), barrier height (4Φ_B), leakage current (I₀) and series resistance (R_s) were studied by the I-V method as a function of annealing temperature as per the Thermionic Emission method (TE). The barrier height varies from 0.84 to 0.73 eV and the device ideality has improved at higher annealing temperature.

     

Determination of Electrical and Photoelectrical Properties of Schottky Diodes Made Using New Chitin Derivatives Synthesized as Interface Layer

Silicon - 5-(2,4-dichlorophenyl)-2-furoic acid and anthraquinone-2-carboxylic acid were reacted separately with chitin. The synthesized products were characterized by various spectroscopic methods...     

Al/P-Si/Coumarin:TiO2/Al Organic-Inorganic Hybrid Photodiodes: Investigation of Electrical and Structural Properties

Silicon - In this study, Coumarin:TiO2 thin films synthesized by sol-gel method in different coumarin weight ratios were formed by drop casting technique on p-Si. The structural and electrical...     

The Effects of Thermal Neutron Irradiation on Current-Voltage and Capacitance-Voltage Characteristics of Au/n-Si/Ag Schottky Barrier Diodes

Silicon - To observe the neutron transmutation and displacement damage effects, Au/n-Si/Ag Schottky barrier diodes were exposed to thermal neutron irradiation. Irradiation induced changes in...     

Optical,Electrical and Photoresponse Properties of Si-based Diodes with NiO-doped TiO2 Film Prepared by Sol-gel Method

Silicon - The Ti1−xO2NixO films (x = 0.0, 0.05, 0.10 and 0.15) with various NiO contents were prepared by sol-gel technique. The prepared films were coated on n-Si substrate by spin coating...     

薄膜中ZnO/Ag的相对厚度对电学性能的影响

银作为低辐射镀膜玻璃的功能层,保证了低辐射镀膜玻璃具有优异的热力学性能.截至目前,银在低辐射镀膜玻璃中仍然起着不可替代的作用.而银层生长质量的好坏则决定了低辐射镀膜玻璃产品性能的好坏.通过对膜层结构中ZnO/Ag的相对厚度对电学性能的研究,当同时满足ZnO的厚度为4nm,Ag的厚度为10nm时,膜层的电学性质最为优异.     

Frequency and Temperature Dependence of Dielectric Properties of Au/Polyvinyl Alcohol (Co,Ni-Doped)/n-Si Schottky Diodes

The dielectric properties and AC conductivity of Au/polyvinyl alcohol (Co, Ni-doped)/n-Si Schottky diodes (SDs) were investigated in the frequency range 1 kHz–1 MHz and in the temperature range 80–400 K. The frequency and temperature dependence of dielectric constant (?′), dielectric loss (?″), loss tangent (tan δ), AC electrical conductivity (σ _ac ) and the real and imaginary parts of the electric modulus (M′ and M″) were found to be a strong function of frequency and temperature. The values of ?′, ?″ and tan δ decrease with increasing frequency, while they increase with increasing temperature, especially above 275 K. The values of σ _ac increase with both increasing frequency and temperature. Such temperature-related behavior of σ _ac can be attributed to the high mobility of free charges at high temperature. Electric modulus formalism was also analyzed to obtain experimental dielectric data. The values of M′ and M″ increase with increasing frequency, while they decrease with increasing temperature. The interfacial polarization, which more easily occurs at low frequencies and high temperatures, consequently contributes to the improvement of the dielectric properties of SDs.     

Electrical Properties of MOS Capacitor with TiO2/SiO2 Dielectric Layer

Silicon - The TiO2/SiO2 film being the dielectric layer was grown on the n-Si wafer using radio frequency (RF) magnetron sputtering. Thus, the Au/TiO2/SiO2/n-Si metal-oxide-semiconductor (MOS)...     

Synthesis and Morphological Study of Nanoparticles Ag/TiO2 Ceramic and Bactericidal Investigation of Polypropylene-Ag/TiO2 Composite

Antibacterial ceramic consisting silver nanoparticles in TiO₂ (rutile phase) particles were prepared via the chemical deposition route. Structure of synthesized ceramic was characterized using different methods of spectroscopies including; X-ray diffraction (XRD), TEM, and scanning probe microscopy (SPM). The results show that very fine silver particles were loaded on the titania dispersedly and also no crystalline change happened in the TiO₂ structure. In order to preparation of antibacterial composite, ceramic was compounded into polypropylene using a Hakke internal mixer in optimized conditions. Morphology of composite was confirmed by AFM images. Finally, antibacterial activity of composite was studied against Staphylococcus aureus. Results show that the bactericidal effect of this composite is significant and suggesting the composite to be promising candidate for applications in fields.     

Low temperature CO oxidation over Au/TiO2 and Au/SiO2 catalysts

After a high-temperature reduction (HTR) at 773 K, TiO₂-supported Au became very active for CO oxidation at 313 K and was an order of magnitude more active than SiO₂-supported Au, whereas a low-temperature reduction (LTR) at 473 K produced a Au/TiO₂ catalyst with very low activity. A HTR step followed by calcination at 673 K and a LTR step gave the most active Au/TiO₂ catalyst of all, which was 100-fold more active at 313 K than a typical 2% Pd/Al₂O₃ catalyst and was stable above 400 K whereas a sharp decrease in activity occurred with the other Au/TiO₂ (HTR) sample. With a feed of 5% CO, 5% O₂ in He, almost 40% of the CO was converted at 313 K and essentially all the CO was oxidized at 413 K over the best Au/TiO₂ catalyst at a space velocity of 333 h^–1 based on CO + O₂. Half the chloride in the Au precursor was retained in the Au/TiO₂ (LTR) sample whereas only 16% was retained in the other three catalysts; this may be one reason for the low activity of the Au/TiO₂ (LTR) sample. The reaction order on O₂ was approximately 0.4 between 310 and 360 K, while that on CO varied from 0.2 to 0.6. The chemistry associated with this high activity is not yet known but is presently attributed to a synergistic interaction between gold and titania.     

CO adsorption and oxidation on Au/TiO2

Preoxidized Au/TiO₂ showed no initial activity during a first heating stage up to 70°C, while prereduction yielded a high initial CO conversion at room temperature. With FTIRS, two different CO absorption bands were detected. One band is usually attributed to CO on an oxidic gold species (2151 cm^-1), the other one is characteristic of CO on metallic gold (2112 cm^-1). The presence of the first species appears to have a detrimental effect on the CO oxidation by O₂. The present results do not support a model in which the activity of supported gold catalysts in CO oxidation is ascribed to ionic Au particles. This revised version was published online in July 2006 with corrections to the Cover Date.     

双效功能型复合光催化剂Ag/TiO2/AC的制备及光催化活性

以硝酸银、四氯化钛及活性炭为原料,采用溶胶-凝胶法和浸渍法制备了3种复合光催化剂。通过TEM、XRD、BET和UV-Vis光谱对复合光催化剂的形貌、物相组成、比表面积和吸光性能进行了表征,并以甲基橙的脱色降解为模型反应,考察了样品的光催化性能。结果表明:其光催化活性大小顺序为Ag/Ti O2/ACAg/Ti O2Ti O2,其中,Ag/Ti O2/AC由于具有895.21 m2/g的比表面积和Ag的负载改性而具有吸附、光催化双效功能,且对光的吸收扩展到可见光区,对甲基橙的最大降解率能达到95.2%。催化剂连续重复使用5次,Ag/Ti O2/AC对甲基橙溶液的脱色降解率均保持在90%以上。     

双相等离子体Au/TiO2纳米复合材料抗菌研究

具有独特的表面等离子体共振（SPR）的金属纳米晶体是一种良好的宽带隙半导体可见光敏化材料。本研究通过溶剂热和煅烧合成了0.3％摩尔比的金修饰氧化钛（Au/TiO2）纳米复合材料。利用X射线晶体衍射（XRD）,X射线光电子能谱（XPS）,透射电子显微镜（TEM）和紫外-可见（UV-vis）等方法对合成的Au/TiO2纳米复合材料进行表征。结果表明,由于强的表面等离子体共振效应,Au纳米颗粒可以显著提高TiO2的可见光吸收性能。随着煅烧温度的升高,可见光吸收峰从?550 nm红移到670 nm,这便于更好地利用太阳光谱。Au/TiO2纳米复合材料对大肠杆菌（E. coli）的抗菌活性显示,在450 ℃下煅烧后形成的金修饰的锐钛矿相和金红石相的混晶相,具有最好的光催化抗菌活性。     

PEG分子量对TiO2微观结构和光催化性能的影响

采用溶胶-凝胶法制备了不同分子量的PEG改性的TiO2光催化材料(PEG-TiO2).利用X射线衍射仪和拉曼光谱,表征和分析了PEG-TiO2的微观结构,以亚甲基蓝溶液为降解对象,评价了不同分子量的PEG-TiO2的光催化性能.实验结果表明,制备的PEG-TiO2为锐钛矿和金红石的混合晶体结构,其中,锐钛矿含量与PEG...     

有机玻璃基底镀TiO2/Au/TiO2膜用底涂层的制备

以溶液聚合工艺制备了数均分子量在20000左右、羟基值为40～48mgKOH/g的丙烯酸树脂,将该树脂与固化剂N-75按适宜的比例混合为底涂层,淋涂于800mm×400mm的洁净有机玻璃(PMMA)表面,在真空镀膜机中依次沉积TiO2膜和Au膜,获得了PMMA/底涂/TiO2/Au/TiO2膜。研究了不同配方的丙烯酸树脂合成工艺和混合溶剂的选择及配比对PMMA/底涂/TiO2/Au/TiO2膜性能的影响,讨论了"形变"的原因。研究发现,当乙酸丁酯和丙二醇甲醚醋酸酯以1∶1的质量比为混合溶剂,树脂和混合溶剂的质量比为1∶3时,所得涂膜具有良好的附着力。以Tego270为助剂,其质量分数为0.2%时能有效减少薄膜的"形变"缺陷。     

Phosgene-Free Photocatalytic Degradation of TCE and PCE Vapors with Au/TiO2

Photocatalytic oxidation of trichloroethylene (TCE) and tetrachloroethylene (PCE) in air had been carried out with TiO₂ film alone and Au/TiO₂ film. On the TiO₂ film TCE and PCE were converted mainly into toxic COCl₂, while COCl₂ free TEC and PCE oxidation could be achieved with Au/TiO₂.     

Ag/TiO2纳米催化剂的制备及性能

采用溶胶-凝胶法制备了Ag/TiO₂光催化剂。通过X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)、N₂吸附-脱附(BET)、透射电子显微镜(TEM)对产物进行了表征。以亚甲基蓝(MB)为降解物,考察了不同Ag含量和不同煅烧温度对样品的光催化性能影响。结果表明,掺杂Ag后,增大了样品的比表面积,800℃时,Ag的引入抑制了TiO₂锐钛矿向金红石相的转变,掺杂后TiO₂的光催化活性大大提高,在500℃煅烧温度下,当Ag的摩尔分数为1%时,在紫外光照射下,经过180min光催化实验,对MB的降解率达到90%.