Effect of Variations in Annealing Temperature and Metallic Cations on Nanostructured Molybdate Thin Films

Crystalline molybdate thin films were prepared by the complex polymerization method. The AMoO₄ (A = Ca, Sr, Ba) films were deposited onto Si wafers by the spinning technique. The Mo–O bond in the AMoO₄ structure was confirmed by FTIR spectra. X-ray diffraction revealed the presence of crystalline scheelite-type phase. The mass, size, and basicity of A²⁺ cations was found to be dependent on the intrinsic characteristics of the materials. The grain size increased in the following order: CaMoO₄ < SrMoO₄ < BaMoO₄. The emission band wavelength was detected at around 576 nm. Our findings suggest that the material’s morphology and photoluminescence were both affected by the variations in cations (Ca, Sr, or Ba) and in the thermal treatment.     

Visible-light Photodegradation of Higher Molecular Weight Organics on N-doped TiO2 Nanostructured Thin Films

Nitrogen doped titania nanoparticles were synthesized and deposited as thin films onto glass slides for photodecomposition studies of high molecular weight organics. The decomposition of stearic acid and polyethelyne glycol (PEG) on the nanostructured thin films under visible light irradiation were monitored using FTIR spectroscopy and a decrease in C–H stretch peak area in the 2,700–3,000 cm⁻¹ range was monitored as the organic molecules were photocatalytically destroyed. Conversely, irradiation with visible light only or the whole Xenon lamp spectrum did not result in the degradation of the stearic or PEG coatings on glass in the absence of the nanocatalysts, which demonstrates for the first time visible light photoactivity of nitrogen-doped titania nanoparticle films.     

气体流量对热解法制备TiO2薄膜性能的影响

通过改变镀膜材料气体流量,研究热解法在线制备TiO2薄膜性能的影响.采用SEM、EDS分析了膜层表面微观形貌、断面厚度和碱腐蚀前后膜层的化学组成,采用分光光度计分析了镀膜玻璃的光学性能和颜色指标,并配制5 mol/L的NaOH溶液对薄膜的耐碱性能进行测试.结果表明:随着气体流量增大,TiO2晶体的颗粒度逐渐增大,晶体密...     

沉积温度对AZO薄膜性能的影响

在采用直流磁控溅射制备AZO(Aluminum Doped Zinc Oxide,掺铝氧化锌)薄膜的过程中,AZO薄膜的光电性能取决于镀膜过程中的各种工艺参数,包括溅射气压、沉积温度、溅射功率和靶基距等。本文主要研究在固定其它工艺参数不变的情况下,通过改变沉积温度在不同的温度下分别制备AZO薄膜,利用SEM、X射线衍射仪等测试不同AZO薄膜的微观结构,并分析研究不同沉积温度下制备AZO薄膜光电性能及结构的变化特性,以筛选出制备高质量AZO膜的最佳沉积温度。     

工艺参数对TiO2薄膜性能的影响

研究了基本工艺参数（如聚乙二醇的添加量和分子量、热处理制度、薄膜层数）对溶胶凝胶法制备TiO2薄膜性能的影响。结果表明：添加分子量2000的聚乙二醇1．0g（相对于100ml溶胶）,以2℃/min的速度缓慢升温至550℃,保温1h,制得的TiO2 10层薄膜,表现出分解稀醋酸的光催化活性较好。     

TiO2-SnO2薄膜的湿敏性能研究

采用溶胶-凝胶工艺在印有梳状银电极的石英玻璃表面制备了不同含量Sn2+掺杂的氧化钛薄膜,通过烧结制得一系列湿敏元件,研究了Sn2+掺杂量、烧结温度和工作频率对薄膜湿敏性能的影响.研究表明,较低的工作频率下元件的湿敏性能较好;Sn2+的加入不同程度地降低了TiO2基薄膜的阻抗值,其中TiO2-15wt%SnO2薄膜表现出最高的灵敏度;薄膜高的湿敏性能与Sn2+掺杂引起的晶粒度变化以及热处理过程中的晶型转变有关.     

热处理温度对铝酸锶长余辉薄膜结构和发光性能的影响

利用磁控溅射制备稀土掺杂铝酸锶薄膜前驱体,再将前驱体置于800℃、900℃、1000℃和1100℃弱还原气氛热处理,得到铝酸锶长余辉发光薄膜。薄膜的物相结构随热处理温度升高而发生改变,逐渐由SrAl₂O₄相转变为Sr₄Al₁₄O₂₅相,光致发光性能随之发生改变。     

不同退火温度In掺杂ZnO薄膜的表面形貌和光学性质

用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和紫外-可见分光光度计观察4%(原子分数)In掺杂ZnO薄膜的微结构、表面形貌和光学性质.微结构分析表明:薄膜仍为六角纤锌矿结构,由于In杂质的掺入,使得薄膜结晶度劣化,退火温度对薄膜微结构影响较小;表面形貌观察结果显示:薄膜表面凹凸不平,450 ℃退火处理薄膜表面最平坦,尺寸在50～100 nm之间小颗粒致密、均匀地分布于起伏的表面;紫外可见透射谱研究结果表明:随着退火温度升高,薄膜光学带宽E_g由3.267 eV减小到3.197 eV,该结果可能与薄膜表面残余应力发生变化密切相关.     

Cl离子掺杂对钙钛矿薄膜结构及光学性能的影响

有机-无机杂化钙钛矿光吸收层薄膜的结构、形貌及结晶度对电池的光电性能起决定性作用.采用一步溶液法通过改变CH3 NH3 I和PbCl2的摩尔比调控钙钛矿前驱体溶液中Cl离子的掺杂量,从而制备钙钛矿光吸收层薄膜.利用荧光光谱(PL)、X射线衍射(XRD)、扫描电子显微镜(SEM)及EDS能谱分别对钙钛矿溶液的荧光性能、薄膜的结构、表面形貌及反应后Cl离子的含量进行表征.结果表明,随着CH3 NH3 I和PbCl2的摩尔比的增加,前驱体溶液的荧光强度逐渐减弱(激发波长为325 nm);晶体结构由立方相CH3 NH3 PbCl3转换成了纯的四方相CH3 NH3 PbI3钙钛矿薄膜,晶粒尺寸增大,晶格应变随之增加;表面覆盖率逐渐升高,薄膜表面无针状结构出现;薄膜中Cl离子的含量逐渐减少,改善了薄膜的质量.     

Annealing Temperature Effect on Bismuth Induced Crystallization of Hydrogenated Amorphous Silicon Thin Films

Silicon - In this work, we emphasis on the Bismuth induced crystallization of hydrogenated amorphous silicon (a-Si) thin films. 50&nbsp;nm of bismuth thin films are deposited by vapor...     

TiO2薄膜材料的制备及其性能的研究进展

TiO2是一种宽带隙半导体材料,具有广阔的应用前景。综述了TiO2薄膜材料的制备方法及其气敏、光电、光催化性能,并对TiO2薄膜材料的发展趋势进行了展望。     

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.

     

退火处理对玻璃表面沉积的ZnO薄膜微观形貌与性能的影响

以Zn(NO3)2·6H2O为前驱体,采用超声喷雾热解法在500℃下、在钠钙硅浮法玻璃衬底上制备了ZnO薄膜.分别在不同温度(500、550、600℃)和不同时间(30、60、120min)对制备的ZnO薄膜进行了退火处理.研究退火条件对ZnO薄膜微观结构、形貌以及光学性能的影响.结果表明:退火处理能提高ZnO薄膜的c轴取向;随着退火时间的延长,ZnO薄膜附着强度随之增加,但c轴取向度呈先增强,至120min时又开始呈下降的趋势;随着退火温度的升高,ZnO薄膜的c轴取向亦出现先显著增强,之后又开始下降的趋势,同时可见光透过率亦呈相同的变化趋势.最佳退火条件为500℃温度保温60min,此时薄膜不仅c轴取向生长优势明显,结晶质量良好,表面颗粒大小均匀,致密平滑,同时薄膜的可见光透过率由退火前的70％提高到90％.     

Effect of Low Concentration Sn Doping on Optical Properties of CdS Films Grown by CBD Technique

Thin and transparent films of doped cadmium sulfide (CdS) were obtained on commercial glass substrates by Chemical Bath Deposition (CBD) technique. The films were doped with low concentration of Sn, and annealed in air at 300 °C for 45 min. The morphological characterization of the films with different amounts of dopant was made using SEM and EDAX analysis. Optical properties of the films were evaluated by measuring transmittance using the UV-vis spectrophotometer. A comparison of the results revealed that lower concentration of Sn doping improves transmittance of CdS films and makes them suitable for application as window layer of CdTe/CIGS solar cells.     

The Effect of Drying Temperature on Physical Properties of Thin Gelatin Films

The molecular morphology of thin gelatin films, controlled through the casting temperature, was monitored by wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). Gelatin films dried at lower temperatures had a markedly higher crystalline or helical structure with a slightly higher T_g and lower ΔC_p compared with hot dried films, which had a more coiled structure. The relationship between molecular morphology and gelatin-water interaction in terms of hydration behavior and water diffusivity was assessed using dynamic vapor sorption (DVS). The sorption capacity increased and the level of hysteresis decreased with increasing the degree of crystallinity. The difference in the aging behavior of the films was explained in terms of the difference between the glass transition and aging temperatures, (Tg – Ta).     

Nd掺杂对ZnSe薄膜微结构的影响

利用真空蒸发的方法制备ZnSe多晶薄膜,并采用双源法对薄膜进行了稀土元素Nd的掺杂。对薄膜进行了XRD测试,并计算了薄膜的晶粒尺寸、晶格常数以及内应力。结果表明,当原子配比Zn∶Se=0.9∶1时可制备较理想的ZnSe多晶薄膜,稀土Nd掺杂并未改变样品的物相结构,掺杂使得薄膜的晶粒尺寸减小,晶胞体积增加,内应力和晶格常数改变。实验还发现,适度的轻掺杂Nd可增加ZnSe薄膜的光透射性。     

钼离子掺杂对TiO2薄膜光催化性能的影响

采用溶胶法制备TiO2溶胶,用浸渍-提拉方式在普通玻璃表面制成锐钛矿相TiO2薄膜.实验结果表明:最佳镀膜次数为3次;掺杂Mo离子对于提高TiO2膜的光催化活性有明显的促进作用.对薄膜的结构进行了表征:用电镜分析(SEM)及X射线衍射法(XRD)确定了晶型及晶粒的大小;用光电子能谱(XPS)测定了其微观成分及含量.     

退火时间对Bi/Te多层薄膜结构和热电性能的影响

采用磁控溅射法在玻璃衬底上室温沉积厚度不同的Bi/Te多层薄膜,在氩气保护下对薄膜在150℃进行不同时间退火处理,研究了退火时间对Bi/Te多层薄膜物相组成、微观形貌、表面粗糙度和热电性能的影响。结果表明:退火过程使Bi、Te原子在相邻单质层界面上产生了强烈的扩散反应,生成以Bi_2Te_3为主相的Bi-Te化合物;随退火时间的延长,薄膜的界面空洞增多,表面粗糙度变大。短时间退火可提高薄膜的热电性能;而随退火时间的延长,量子尺寸效应逐渐显现,薄膜的载流子浓度、迁移率、电导率和Seebeck系数均出现明显的振荡现象,沉积的单质层越厚,振荡周期越大。     

Sn掺杂对ZnO压敏变阻器电学性能的影响

本文采用沉淀法以SnCl2·H2O代替SbCl3制备了ZnO压敏变阻器.分析了SnO2含量对变阻器电学性能的影响.随着SnO2含量的增加,漏电流和压敏电压明显增大;而非线性系数在SnO2掺杂量达到3.0 mol％时达到极大值.通过适当的掺杂,得到了漏电流为0.08 μA,非线性系数为80.3,压敏电压为1006.7 V1mA/mm性能良好的ZnO变阻器.     

Influences of Cr Doping on the Electrical Properties in BiFeO3 Thin Films

Cr-doped BiFeO₃ (BFO) thin films were deposited on Pt(200)/TiO₂/SiO₂/Si(100) substrates by a chemical solution deposition method. The dielectric constant and dissipation factor of the BFO thin films decrease from 165 and 0.054 (undoped) to 100 and 0.02 (3 mol% Cr-doped) at a frequency of 10 kHz as the Cr content increases. The leakage current and ferroelectric properties were improved significantly by means of Cr doping. The leakage current density of 4.1×10^-6 A/cm² for the 3 mol% Cr-doped BFO thin film is about four orders of magnitude lower than that of undoped BFO thin film at an external electric field of 100 kV/cm. The 3 mol% Cr-doped BFO thin film exhibited a well-saturated hysteresis loop with a large remanent polarization (P_r) of 61 μC/cm² at room temperature. The reason for the improved leakage current and ferroelectric properties in Cr-doped BFO thin films can be attributed to the reduced oxygen vacancies in the films by Cr doping.

Communicated by Dr. George W. Taylor