溶胶-凝胶法制备ZAO薄膜及其结构与光学性能分析

以Zn（CH3COO）2·2H2O和Al（NO3）3·9H2O为主要原料,采用溶胶一凝胶法结合旋涂工艺以ITO玻璃为衬底制备获得掺Al型氧化锌透明导电薄膜（Zn2Al0.6O）。分别采用XRD和分光光度计测试分析了所制各薄膜的结构和透射光谱,并计算了薄膜的平均晶粒尺寸和光学带隙。结果表明,所制备薄膜为ZAO薄膜：薄膜平...     

PLLA-PDLA共聚物薄膜的结晶形态

利用旋涂法制备一系列的聚左旋-右旋乳酸共聚物（PLLA-PDLA）薄膜,对其进行等温结晶处理。利用差示扫描量热仪、原子力显微镜、X-射线衍射仪等手段研究了体系的热性能、结晶形态、晶体结构等性能。结果表明,PLLA-PDLA共聚物在128～153 ℃呈现明显结晶峰,利用原子力显微镜得到PLLA-PDLA共聚物样品在不同温度、不同浓度、不同时间、不同溶剂、不同基底条件下的结晶形态,得到不同尺寸的棒状和支化结构晶体,尤其在玻璃基底上形成细的支化结构且互相缠绕,表面的覆盖密度比硅片高的结晶形态。X-射线衍射分析表明在12.01 °、20.88 °和24.18 °处出现明显的结晶衍射峰。     

Y2O3：Eu^3＋薄膜的制备及发光性能的研究

以稀土氧化物为原料，用溶胶-凝胶法制备前驱液，加入适量的聚乙烯醇做成膜物质，用浸渍拉提法在石英玻璃表面上得到均匀的薄膜，然后经过适当的干燥和热处理得到Y2O3：Eu^3＋发光薄膜．讨论了Eu^3＋的掺杂浓度和热处理温度对薄膜发光性能的影响．试验表明：Eu^3＋的最佳掺杂浓度为8％（摩尔分数），薄膜的发光性能随热处理温度提高而增强，当热处理温度达到700℃后，薄膜的发光性能基本上稳定．同时用原子力显微镜和X射线衍射分析了薄膜的表面形貌和结构．     

溶胶凝胶法制备PbTiO3薄膜的研究

利用ＩＲ、ＤＴＡ、ＴＧ、ＸＲＤ及Ｒａｍａｎ光谱等测试手段,研究了乙酰丙酮改性的Ｐｂ－Ｔｉ系统的溶胶凝胶过程。结果表明通过乙酰丙酮的改性可以得到稳定的溶胶前驱体,由此溶胶制备的薄膜在６００℃即形成完全晶化的钛酸铅薄膜。     

双离子束溅射非晶SiOxNy薄膜的光致发光研究

采用双离子束溅射法制备了SiOxNy薄膜,用X射线衍射分析(XRD),透射电子显微镜(TEM),X射线光电子能谱(XPS),傅立叶变换红外(FTIR)等对薄膜的结构进行了表征,分析了样品的光致发光(PL)特性。X射线衍射(XRD),透射电子显微镜(TEM)结果表明该薄膜具有非晶结构。XPS测试表明N1s的特征峰位于398eV,对应于N-Si键。在光吸收谱中,与Si-SiO2薄膜相比,SiOxNy的光学带隙得到展宽。在225nm的激光激发下,样品在室温下可发射可见光,峰位位于590nm,与N的缺陷有关。     

陶瓷薄膜的Sol—Gel法制备

本文从凝胶制备途径,即无机途径和有机途径角度,阐述了各途径溶胶－凝胶化过程的特点以及凝胶膜向陶瓷薄膜转化的过程。     

Y_2O_3∶Eu~(3 )薄膜的制备及发光性能的研究

以稀土氧化物为原料,用溶胶-凝胶法制备前驱液,加入适量的聚乙烯醇做成膜物质,用浸渍拉提法在石英玻璃表面上得到均匀的薄膜,然后经过适当的干燥和热处理得到Y2O3∶Eu3 发光薄膜.讨论了Eu3 的掺杂浓度和热处理温度对薄膜发光性能的影响.试验表明:Eu3 的最佳掺杂浓度为8%(摩尔分数),薄膜的发光性能随热处理温度提高而增强,当热处理温度达到700℃后,薄膜的发光性能基本上稳定.同时用原子力显微镜和X射线衍射分析了薄膜的表面形貌和结构.     

聚氧乙烯超薄膜等温结晶过程的研究

利用原子力显微镜(AFM)研究了不同温度的聚氧乙烯(PEO)超薄膜等温结晶过程。结果表明:超薄膜晶体形貌具有生长控制因素的依赖性;当晶体生长同时受到表面成核和熔体扩散控制时,各方向生长速率明显不同,且在晶体形成过程中,先发生液相-固相转变,后发生固相-固相转变。     

电沉积法制备CIGS薄膜的工艺研究

电镀液中GaCl3的浓度对电沉积法制备的CIGS薄膜光电性能有明显的影响,通过研究样品的开路光电压,找到了最优浓度.用退火工艺处理样品,可以获得平滑、致密的薄膜,且能增大薄膜中CIGS的结晶程度和含量.通过测试CIGS薄膜的XRD图谱,得知薄膜晶型为黄铜矿型.     

砷化镓上生长金刚石薄膜的研究

以CH4和H2为气源,用微波辅助等离子体装置,在10.0 mm×7.0 mm的砷化镓基底上沉积了CVD金刚石薄膜,用扫描电子显微镜观察沉积效果,拉曼光谱表征沉积质量,分析薄膜附着力与砷化镓材料性能的关系。结果表明,当基体温度为600℃,气压为5 kPa,甲烷浓度为2.0%时,在砷化镓片表面上沉积出了CVD金刚石薄膜,晶粒尺寸均匀,晶形完整、规则,晶界非常清晰。     

Structural and optical properties of ZnS thin films deposited by RF magnetron sputtering

Zinc sulfide [ZnS] thin films were deposited on glass substrates using radio frequency magnetron sputtering. The substrate temperature was varied in the range of 100°C to 400°C. The structural and optical properties of ZnS thin films were characterized with X-ray diffraction [XRD], field emission scanning electron microscopy [FESEM], energy dispersive analysis of X-rays and UV-visible transmission spectra. The XRD analyses indicate that ZnS films have zinc blende structures with (111) preferential orientation, whereas the diffraction patterns sharpen with the increase in substrate temperatures. The FESEM data also reveal that the films have nano-size grains with a grain size of approximately 69 nm. The films grown at 350°C exhibit a relatively high transmittance of 80% in the visible region, with an energy band gap of 3.79 eV. These results show that ZnS films are suitable for use as the buffer layer of the Cu(In, Ga)Se₂ solar cells.     

Electronic phase transition in CrN thin films grown by reactive RF magnetron sputtering

Chromium nitride thin films were prepared by reactive radio frequency magnetron sputtering on glass and Si(001) substrates. Thin films were grown at different nitrogen to argon flow rate ratio and their effect on the film composition, band gap and electronic phase transition was studied by different experimental technique. X-ray diffraction analyses establish that CrN films predominantly grow in [111]_CrN and [002]_CrN directions irrespective of the substrates used for the growths. The band gap was found to vary with the composition of the films. All films are semiconducting at room temperature and show discontinuity in their resistivity versus temperature curve indicating electronic transition. But the low temperature electronic phase depends on the growth conditions and composition of the films.     

Improved physical properties of Al-doped ZnO thin films deposited by unbalanced RF magnetron sputtering

Room temperature Al-doped ZnO (AZO) thin films with improved crystalline and optical properties were grown on normal glass substrates using unbalanced RF magnetron sputtering technique. To modify the plasma density towards the substrate and enhance the crystalline nature, an additional magnetic field ranging from 0 to 6.0 mT has been applied to the AZO target by proper tuning of solenoid coil current from 0 to 0.2 A respectively, which plays a significant role for controlling the physical properties of AZO films. The results from XRD studies indicate that all AZO films were composed of hexagonal wurtzite structure with better crystal quality through the applied magnetic field, ZnO (002) plane as a preferred growth. Furthermore, XPS studies suggested that symmetric chemical shifts in the binding energies for the Zn 2p and O1s levels with applied magnetic field. SEM analysis revealed the formation of a smooth, homogeneous and dense morphological surface with applied magnetic field. From AFM analysis, it was observed that the applied magnetic field strongly influenced the grain size and the films showed decreasing tendency in electrical resistivity. Films exhibited superior optical transmittance more than 94% in the visible region essentially due to the formation of better crystalline nature. The results indicate that improved band gap from 3.10 to 3.15 eV with additional magnetic field varied from 0 to 6.0 mT respectively.     

Structural and nanomechanical properties of BiFeO3 thin films deposited by radio frequency magnetron sputtering

The nanomechanical properties of BiFeO₃ (BFO) thin films are subjected to nanoindentation evaluation. BFO thin films are grown on the Pt/Ti/SiO₂/Si substrates by using radio frequency magnetron sputtering with various deposition temperatures. The structure was analyzed by X-ray diffraction, and the results confirmed the presence of BFO phases. Atomic force microscopy revealed that the average film surface roughness increased with increasing of the deposition temperature. A Berkovich nanoindenter operated with the continuous contact stiffness measurement option indicated that the hardness decreases from 10.6 to 6.8 GPa for films deposited at 350°C and 450°C, respectively. In contrast, Young''s modulus for the former is 170.8 GPa as compared to a value of 131.4 GPa for the latter. The relationship between the hardness and film grain size appears to follow closely with the Hall–Petch equation.     

Dielectric properties of amorphous BaTiO3 films deposited by RF magnetron sputtering

In the present paper, dielectric properties of a-BaTiO₃ films have been investigated as a function of frequency (10⁻¹ to 10⁵ Hz) and temperature (25–350 °C) using the dielectric spectroscopy technique. Relaxation and ac-conductivity processes were analyzed in order to study charge transport in the bulk and at the electrode-film interfaces. It seems that the oxygen vacancies play an essential role in both processes.     

The optical and electrical properties of ZnO:Al thin films deposited at low temperatures by RF magnetron sputtering

Several ZnO:Al thin films have been successfully deposited on glass substrates at different substrate temperatures by RF (radio frequency) magnetron sputtering method. Effects of the substrate temperatures on the optical and electrical properties of these ZnO:Al thin films were investigated. The UV–VIS–NIR spectra of the ZnO:Al thin films revealed that the average optical transmittances in the visible range are very high, up to 88%. X-ray diffraction results showed that crystallization of these films was improved at higher substrate temperature. The band gaps of ZnO:Al thin films deposited at 25 ℃, 150 ℃, 200 ℃, and 250 ℃ are 3.59 eV, 3.55 eV, 3.53 eV, and 3.48 eV, respectively. The Hall-effect measurement demonstrated that the electrical resistivity of the films decreased with the increase of the substrate temperature and the electrical resistivity reached 1.990×10^?3 Ω cm at 250 ℃.     

Fabrication of CaLa4(Zr0.05Ti0.95)4O15 thin films by RF magnetron sputtering

Crystalline CaLa₄(Zr_0.05Ti_0.95)₄O₁₅ thin films deposited on n-type Si substrates byRF magnetron sputtering at a fixed RF power of 100 W, an Ar/O₂ ratio of 100/0, an operating pressure of 3 mTorr, and different substrate temperatures were investigated. The surface structural and morphological characteristics analyzed by X-ray diffraction and atomic force microscopy were sensitive to the deposition conditions, such as the substrate temperature. The diffraction pattern showed that the deposited films had a polycrystalline microstructure. As the substrate temperature increased, the quality of the CaLa₄(Zr_0.05Ti_0.95)₄O₁₅ thin films improved, and the kinetic energies of the sputtered atoms increased, resulting in a structural improvement of the deposited CaLa₄(Zr_0.05Ti_0.95)₄O₁₅ thin films. A high dielectric constant of 16.7 (f=1 MHz), a dissipation factor of 0.19 (f=1 MHz), and a low leakage current density of 3.18×10⁻⁷ A/cm² at an electrical field of 50 kV/cm were obtained for the prepared films.     

Study of the thermal stability of carbon nitride thin films prepared by reactive magnetron sputtering

CN_x amorphous films have been prepared by reactive magnetron sputtering in a pure N₂ discharge. The films grown on NaCl have been characterised by Fourier transform infrared spectroscopy (IR), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). C/N atomic ratios have been determined by EELS with values in the range 2.0–1.2 for samples grown under different conditions. The thermal stability of the films upon heating in vacuum was followed ‘in situ’ at the transmission electron microscope by EELS. This study has been completed by a thermogravimetric and mass spectrometer analysis of evolved gases upon heating in nitrogen flow and vacuum, respectively. Under these conditions the films are stable up to 1023 K. Above this temperature the films decompose by elimination of nitrogen remaining a carbonaceous residue. The thermal stability of the films upon annealing in air was studied by following the evolution of the X-ray photoelectron spectroscopy (XPS) peaks during heating in air of films grown on steel. Deconvolution analysis of the XPS spectra allows to determine the evolution of the different type of bonds. In particular pure carbon in the films appears more reactive to oxygen than CN and C–N bonds.     

Structural and mechanical properties of CNx thin films prepared by magnetron sputtering

In an attempt to define the role of nitrogen in CN chemical bonding and in the formation of CN_x thin films, several coatings with a variable concentration of N₂ were grown onto (100) Si substrates using magnetron sputtering in N₂/Ar discharge. The chemical composition of the as-deposited films was investigated by means of Rutherford backscattering spectroscopy (RBS) and showed an [N]/[C] ratio up to 0.7. Raman and Fourier transform infrared (FTIR) spectroscopy were carried out to measure the optical vibration properties for studying the bonding state of nitrogen.By means of grazing incidence X-ray diffraction (XRD) and transmission electron microscopy (TEM) electron diffraction the structure of the deposited films was proven to be mainly amorphous containing small crystallites of CN_x compounds. Scanning tunneling microscopy (STM) shows the clusterlike surface of the films where the cluster size is characterized by scaling behaviour. The mechanical properties of the CN_x thin films adhering their substrates were investigated using the nanoindentation technique. From the load–displacement curve the hardness H and the Young's modulus E of the films were calculated.The relationships between deposition parameters and properties of CN_x films are shown and discussed. In particular, the influence of the applied r.f. power and the role of the N₂ partial pressure are demonstrated.