Surface textured molybdenum doped zinc oxide thin films prepared for thin film solar cells using pulsed direct current magnetron sputtering

In this study, we examined the effect of etching on the electrical properties, transmittance, and scattering of visible light in molybdenum doped zinc oxide, ZnO:Mo (MZO) thin films prepared by pulsed direct current magnetron sputtering. We used two different etching solutions - KOH and HCl - to alter the surface texture of the MZO thin film so that it could trap light. The experimental results showed that an MZO film with a minimum resistivity of about 8.9 × 10^− 4 Ω cm and visible light transitivity of greater than 80% can be obtained without heating at a Mo content of 1.77 wt.%, sputtering power of 100 W, working pressure of 0.4 Pa, pulsed frequency of 10 kHz, and film thickness of 500 nm. To consider the effect of resistivity and optical diffuse transmittance, we performed etching of an 800 nm thick MZO thin film with 0.5 wt.% HCl for 3-6 s at 300 K. Consequently, we obtained a resistivity of 1.74-2.75 × 10^− 3 Ω cm, total transmittance at visible light of 67%-73%, diffuse transmittance at visible light of 25.1%-28.4%, haze value of 0.34-0.42, and thin film surface crater diameters of 220-350 nm.     

Al-Mg-B thin films prepared by magnetron sputtering

Hard, nanocomposite aluminum magnesium boride thin films were prepared on Si (100) substrates with a three target magnetron sputtering system. The films were characterized by X-ray diffraction, atomic force microscope, electron micro-probe, Fourier transform infrared spectroscopy and nanoindentation. The results show that the maximum hardness of the as-deposited films is about 30.7 GPa and these films are all X-ray amorphous with smooth surfaces. The influences of substrate temperature and boron sputtering power on the quality of the films are discussed. From the results of this work, magnetron sputtering is a promising method to deposit Al-Mg-B thin films.     

基于磁控溅射的金属氧化物气敏薄膜的研究进展

气体传感器的应用越来越广泛,对气敏材料的研究也越来越深入。磁控溅射法是生产气敏薄膜的一种主要方法,本文重点介绍了用磁控溅射法制备的几种金属氧化物薄膜(SnO2、WO3、ZnO、TiO2、In2O3和NiO等)的气敏性能及其研究进展,对其它薄膜做了简要概述,并提出了目前在气敏薄膜研究中存在的问题。     

Electronic conduction processes in Pt-doped tin oxide thin films prepared by RF magnetron sputtering

Thin films of Pt-doped SnO₂ were prepared by RF magnetron sputtering onto glass substrates maintained at room temperature. Gold electrodes were provided by conventional vacuum evaporation to form sandwich structures. X-ray diffraction measurements confirmed the films to be of an amorphous structure. Room temperature d.c. measurements showed a dominant Poole-Frenkel conduction process at low applied voltages, both under vacuum and in ambient air, but the results of the latter exhibited localized field enhancement caused by various adsorbed oxygen species. At higher voltages space-charge-limited conductivity was observed, with the temperature parameter characterizing the exponential trap distribution decreasing from approximately 1500 to 1050 K as a result of the oxygen adsorption. A.c. conductivity was characterized by an angular frequency, , dependence of the form ^s with an indexs < 1, and was associated with a relaxation process due mainly to a charge-carrier hopping mechanism. Both capacitance and loss tangent decreased with increasing frequency, in accordance with existing theory for samples provided with ohmic contacts.     

Structural and magnetic properties of TiZrNi thin films prepared by magnetron sputtering and thermal annealing

Distinctive thin layers of TiZr and Ni were deposited by using a magnetron sputtering method and a thermal annealing was applied to discover metallic films of quasicrystals. After a heat treatment in vacuum, 70 nm thick deposited layers were well mixed with nominal compositions of 49.7, 29.3 and 21.0 for Ti, Zr and Ni, respectively, which is very close with the one forming a quasicrystalline phase. The magnetization values were significantly decreased from 0.286 to 0.142 emu/mm3 at 2000 Oe, after annealing, while a shape of magnetic hysteresis was maintained. It is believed that a different magnetic behavior after thermal annealing is due to the homogeneous mixing of atomic elements and possible existence of a metastable phase.     

磁控溅射Ni-Mn-Ga薄膜的磁致应变

采用直流磁控溅射的方法,在NaCl基底上沉积了Ni-Mn-Ga薄膜,对薄膜进行了形貌观察、微区成分及结构分析,并测量了薄膜的磁致应变.结果表明,薄膜表面可见大小不一的团簇颗粒,具有明显的岛状结构,表明Ni-Mn-Ga薄膜的形成为典型的核生长型机制.热处理前的薄膜具有部分非晶存在,热处理后薄膜晶化为多晶形态.无约束薄膜在磁场下呈现负的磁致应变,在1.3T磁场下,其最大应变值可达-0.008%,并且可以完全恢复.     

Ellipsometry study of InN thin films prepared by magnetron sputtering

Indium nitride (InN) thin films have been deposited on Si(1 0 0) substrates at temperature of 100–400 °C by reactive radio frequency (RF) magnetron sputtering. We measured the ellipsometric spectra of the InN film samples, and obtained the optical constants for the wavelength range of 410–1100 nm. The absorption edge of the InN films is 1.85–1.90 eV. The thicknesses of various InN films are found to be dependent on the substrate temperature.     

Properties of zirconia thin films prepared by reactive magnetron sputtering

The search for alternative dielectric materials with high dielectric constant, thermodynamic stable on silicon substrate and low direct tunneling current leads to oxide based materials like zirconia. Zirconia thin films were prepared by reactive magnetron sputtering. The capacitance voltage, ac and dc electrical characteristics were investigated and the values like fixed oxide charges were calculated and compared among the samples with and without annealing. Films annealed at 700 °C showed a dielectric constant ∼ 26 with interface trap densities of 1.629 × 10¹² eV^− 1 cm^− 2.     

真空热蒸发镀CIAS薄膜

采用真空热蒸发方法在普通玻璃基底上制备Cu In0.7Al0.3Se2(CIAS)薄膜,并对之进行450℃真空硒化退火处理。结果表明,制备的CIAS薄膜具有黄铜矿结构并且以(112)晶面优先生长。真空硒化退火后,薄膜晶体结构更完整,晶粒长大,成分分布均匀,更接近CIAS晶体的化学计量比。薄膜为P型半导体,退火后的薄膜禁带宽度减小至1.38 e V,带电粒子数下降至2.41E+17 cm-3,带电粒子迁移率增加至5.29 cm2/(N·s),电阻率升高至4.9Ω·cm。     

Amorphous indium tungsten oxide films prepared by DC magnetron sputtering

Indium-tungsten-oxide (IWO) films were prepared by dc magnetron sputtering at ambient substrate temperature (T_s). Characteristics of the films were compared with those of In₂O₃–SnO₂ (ITO) thin films prepared under the same condition. The sputter-deposited IWO films have entirely amorphous structure with an average transmittance of over 85% in the visible range and exhibit a minimum resistivity of 3.2 × 10^–4cm at W content [W/(In + W)] of 0.57 at.%. An in-situ heating X-ray diffraction measurement have shown that the crystallization temperature of IWO films is higher than those of ITO films (150–160C) and increases with increasing W content. This enabled a smooth amorphous surface of IWO films as compared with a rough surface of partially crystallized ITO films as revealed by an atomic force microscopy. IWO films are useful for transparent electrode of organic light emitting diode and polymer LCDs because of the low resistivity, high transparency and smooth surface obtainable by the conventional dc magnetron sputtering at room temperature.     

Photoelectrochemical properties of nitrogen-doped indium tin oxide thin films prepared by reactive DC magnetron sputtering

Nitrogen-doped indium tin oxide (N-ITO) thin films are deposited on unheated ITO glass substrates in this study. The structural properties of the N-ITO thin films, determined by X-ray diffraction (XRD) and Raman scattering, show that the indium nitride (InN) phase is liable to form in N-ITO films prepared in 20% N₂. A broad XRD peak around 2θ = 33° and Raman peak around 490 cm^− 1 are assigned to the InN phase, but no such peak is observed from the ITO film. Hence, the bandgap is narrowed by N-doping for absorbing light of longer wavelengths of ~ 500 nm. However, under illumination by ultraviolet, the N-ITO film prepared in 20% N₂ exhibits the least photocurrent response, which is less than one third that of the N-ITO catalyst that was doped in 16.4% N₂. This result is attributed mostly to the fact that the valence and conduction band potentials are not positioned properly between the newly formed InN and host ITO phases, rendering inefficient inter-semiconductor electron transfer. Therefore, higher N-doped samples exhibit a lower photocurrent response. Interestingly, the N-ITO film prepared in 16.4% N₂ exhibits the highest photocurrent density of about 165.5 μA/cm² at an applied bias of 1.2 V. This implies that the N-ITO films should be prepared at a low N₂ ratio to ensure a favorable photoelectrochemical activity.     

Photoemission study of the tin doped cerium oxide thin films prepared by RF magnetron sputtering

Ce-Sn-O mixed oxide films prepared by simultaneous Sn metal and cerium oxide magnetron sputtering were studied by high resolution photoemission. The analysis showed that the degree of reduction of the cerium oxide depends on the tin concentration in the film. Ce⁴⁺ → Ce³⁺ conversion is explained by a charge transfer from Sn atoms to unoccupied orbital Ce 4f⁰ of cerium oxide by forming Ce 4f¹ state. The X-ray Photoelectron Spectroscopy data were compared with study of the single-crystalline CeO₂ thin films and Sn/CeO₂(111) model system prepared and studied in situ excluding air exposure effects.     

Titanium oxide thin films deposited by high-power impulse magnetron sputtering

Ionized physical vapor deposition processes are of great interest for surface modification because the flexibility of the thin film deposition process can be increased by ionizing the metallic vapor. Recently, high-power impulse magnetron discharges have been implemented to achieve high ionization rates.Thin films of titanium oxide have been deposited on glass and steel substrates using 450 × 150 mm rectangular titanium target in argon-oxygen atmosphere. The average power delivered to the plasma is ranging between 1.5 and 2 kW and peak current and voltage are respectively 200 A and 900 V.Films are characterized using Scanning Electron Microscopy, Grazing Incidence X-ray Diffraction and Optical Transmission Spectroscopy. One of the major findings is the presence of rutile deposited on steel substrate (even for 0 V bias grounded substrate) and the significant increase of the refractive index of the films deposited on glass compared to thin films deposited via conventional direct current bipolar pulsed magnetron sputtering. Films synthesized by high-power impulse magnetron sputtering are denser.     

氧化钒薄膜作为锂离子微电池阴极膜的磁控溅射技术的制备

研究了用磁控溅射系统来制备氧化钒薄膜,通过优化工艺条件制备出可用作锂离子微电池阴极膜的非晶态五氧化二钒（α-V2O5）薄膜。并使用X射线衍射（XRD）与X射线光电子谱（XPS）来表征薄膜的晶向及化学组分。结果表明通过调节氧气以及氩气的流量、基片的温度和溅射功率,可以制备出高纯度的α-V2O5薄膜。而且,半电池体系V2O5/LiPF6/Li被构造用于表征在锂电池中作为阴极膜的五氧化二钒（α-V2O5）的电学性质。在此电池系统经过10个循环放电后,薄膜放电电容趋于稳定值。     

Electrical characterisation of AlCuMo thin films prepared by DC magnetron sputtering

Thin film resistors have been manufactured to evaluate the electrical performance characteristics of AlCuMo thin films. The films were prepared on Al2O3 substrates at room temperature as a function of Mo concentration by DC magnetron sputtering and were then annealed at various temperatures in air and N2 atmospheres. The effect of annealing temperature on the electrical properties of the films was systematically investigated. Increase in Mo content produced a decrease in temperature coefficient of resistance (TCR), an increase in resistivity (r) and an improvement in long term stability (DV/V) of the films. TCR varied from negative to positive and further improvements in resistance stability of the films were also achieved through increasing annealing temperature in both air and N2 atmospheres. A temperature region is proposed where `near zero? TCR (ppm/8C) and long term stability of better than 0.2% can be realised.     

Characterization of organic polymer thin films deposited by rf magnetron sputtering

Organic polymer thin films deposited by sputtering using polytetrafluoroethylene (PTFE) and polyimide (PI) targets were investigated with Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM). Films deposited from the PTFE target were poly-hydro-fluoro-carbon. The thin films showed water repellency with an H₂O contact angle of about 110° and were transparent in the visible region. C-F combination states in the films were similar to those of bulk PTFE. Films deposited from the PI target were found to contain C-N bonds and were harder than bulk PI. The color of thin films was dark brown, showing the existence of C-N bonds, such as those in imide and/or amide groups. However, the combination states characterized by FTIR and XPS analyses were considerably different from those of bulk PI. The difference in chemical composition and combination states between the films deposited from PTFE and PI is thought to result from the difference in types of particles sputtered from the targets; in the case of PTFE sputtering, less C-F bonds are broken by collision of Ar ions for sputtering, whereas in the case of PI sputtering, C-H and C-C bonds are broken by collision of Ar ions.     

磁控溅射制备SiC薄膜的高温热稳定性

采用磁控溅射方法在Si基底上制备SiC薄膜,研究了SiC薄膜经不同温度和气氛条件高温退火前后结构、成份的变化.结果表明,薄膜主要以非晶为主,由Si-C键,C-C键和少量Si的氧化物杂质组成;在真空条件下经高温退火后,薄膜C-C键的含量减少,而Si-C键的含量增加,真空退火有利于SiC的形成;在800℃空气中退火后,薄膜表面生成一层致密的SiO2薄层,阻止了氧气与薄膜内部深层的接触,有效保护了内部的SiC.在空气条件下,SiC薄膜在800℃具有较好的热稳定性.     

Fluorine-doped ZnO transparent conducting thin films prepared by radio frequency magnetron sputtering

Fluorine-doped ZnO transparent conducting thin films were prepared by radio frequency magnetron sputtering at 150 °C on glass substrate. Thermal annealing in vacuum was used to improve the optical and electrical properties of the films. X-ray patterns indicated that (002) preferential growth was observed. The grain size of F-doped ZnO thin films calculated from the full-width at half-maximum of the (002) diffraction lines is in the range of 18-24 nm. The average transmittance in visible region is over 90% for all specimens. The specimen annealed at 400 °C has the lowest resistivity of 1.86 × 10^− 3 Ω cm, the highest mobility of 8.9 cm² V^− 1 s^− 1, the highest carrier concentration of 3.78 × 10²⁰ cm^− 3, and the highest energy band gap of 3.40 eV. The resistivity of F-doped ZnO thin films increases gradually to 4.58 × 10^− 3 Ω cm after annealed at 400 °C for 4 h. The variation of the resistivity is slight.