基于不同衬底的TCO薄膜的激光刻蚀工艺研究

为了探索对基于不同衬底的透明导电薄膜的图形化制作,研究了采用激光刻蚀基于玻璃和柔性PET衬底的ITO和FTO等TCO薄膜材料的优化工艺,考察了激光设备在不同工作功率和扫描速率下工作对刻蚀效果的影响。结果表明,玻璃基薄膜可采用2.3 W的刻蚀功率和500 mm·s^-1的扫描速率进行刻蚀,柔性PET基薄膜可采用1.2 W的刻蚀功率和500 mm·s^-1的扫描速率进行刻蚀;扫描速率越慢、激光功率越高,对薄膜的刻蚀速率就会越快;激光功率过高会导致柔性PET衬底发生高温热熔化而凸起形变,因此刻蚀时应适当降低刻蚀功率。综合而言,采用激光刻蚀法可高效率、高品质地实现对不同衬底上薄膜的图形化制作。     

A density functional study of structural,electronic and optical properties of titanium dioxide: Characterization of rutile,anatase and brookite polymorphs

Study of fundamental physical properties of titanium dioxide (TiO₂) is crucial to determine its potential for different applications, such as study of electronic band gap energy is essential to exploit it for optoelectronics and solar cell technology. We present here investigations pertaining to structural, electronic and optical properties of rutile, anatase and brookite polymorphs of TiO₂ by employing state of the art full potential (FP) linearized (L) augmented plane wave plus local orbitals (APW+lo) approach realized in WIEN2k package and framed within density functional theory (DFT). To incorporate exchange correlation(XC) energy functional/potential part into total energy, these calculations were carried out at the level of PW–LDA, PBE–GGA, WC–GGA, EV–GGA, and mBJ–GGA which are exploited as the manipulated variables in this work. From our computations, the obtained structural parameters results were found to be consistent with the available experimental results. The analysis of electronic band gap structure calculations point to TiO₂ as a semiconducting material in all three phases, whereas band gap character around Fermi level was found to be indirect for anatase, and direct for rutile and brookite phases. Density of state (DOS) profiles showed a substantial degree of hybridation between O 2p and Ti 3d in conduction and valence band regions, illustrating a strong interaction between Ti and O atoms in TiO₂ compund. In addition, our investigations of the optical properties also endorse the interband transitions from O 2p in valence band to Ti 3d in conduction band.     

Band gap engineering and low temperature transport phenomenon in highly conducting antimony doped tin oxide thin films

A huge band gap tuning and low temperature transport phenomenon in highly transparent antimony doped tin oxide thin film (Sb:SnO₂) under the influence of swift heavy ions irradiation (SHII) is reported. Structural analysis shows an enhancement in crystallinity at initial fluence of irradiation followed by amorphization at higher fluences. Films were also well studied for their surface morphology by atomic force microscopy and scanning electron microscopy. Band gap analysis reveals a drastic band gap narrowing around 1.1 eV upon SHI irradiation. Transport measurements show that the high conductivity and the carrier concentration decrease upon increase in the fluence of irradiation. The mechanism of charge carrier transport investigated at low temperature is attributed to nearest neighbor hopping (NNH) and variable range hopping (VRH) in different temperature regimes. Origin of the band gap tuning is understood in framework of Burstein–Moss (BM) shift, Quantum Confinement (QC) effect and band-tailing states in amorphous semiconductors.     

TCO镀膜玻璃生产线控制系统设计及模块化编程实践

TCO镀膜玻璃是薄膜太阳能电池的重要组成元件,本文详述了我国第一条投入商用的TCO镀膜玻璃生产线控制系统设计过程。简要介绍了采用罗克韦尔自动化最新EthernetIP DLR网络技术的系统结构及其高速率、高可靠性、高扩展性、简单易用等特点。重点介绍了罗克韦尔自动化模块化编程技术在控制系统编程设计实施中基于控制对象的数据封装、模块划分及彼此间关系定义、接口实现和AOI用户自定义程序块的封装等过程。体现出模块化编程相对于传统编程方式给OEM客户所带来的快速创新能力的优势。     

Effects of oxygen concentration on the properties of sputtered SnO2:Sb films deposited at low temperature

Antimony doped tin oxide (SnO₂:Sb) films have been prepared by d.c. magnetron sputtering and the properties of the films depend on deposition conditions, such as O₂ gas ratio, were investigated. The gas composition was found to affect the properties of the films. With the incorporation additional oxygen, the electrical and optical properties of films significantly improved. The minimum value of resistivity of the films was 4.9 × 10^− 3 Ω cm at the oxygen concentration of 30% and the optical transmittance was over 80%.     

透明导电氧化物薄膜的研究现状及展望

综述了TCO薄膜的研究现状，ITO和ZAO薄膜是2种主要的TCO薄膜，其中ITO薄膜是目前应用最广泛的薄膜，ZAO薄膜是目前研究的热点，具有替代ITO的潜能。另外，就透明导电膜目前存在的问题以及发展展望进行了分析讨论。     

Evaluation of surface roughness and nanostructure of indium tin oxide (ITO) films by atomic force microscopy

Indium tin oxide was deposited on a glass (soda lime glass) by radiofrequency sputtering system at different sputtering gas (argon/oxygen 90/10%) pressures (20-34 mTorr) at room temperature. The sputtering rate was affected by the sputtering gas pressure. The optimum sputtering gas pressure was found to be 27 mTorr. The samples at different thicknesses (168, 300, 400, 425, 475, 500 and 630 nm) were deposited on the substrate. Transparency, electrical conductivity and surface roughness of the films were characterized. The samples were annealed at 350, 400 and 450 degrees C to evaluate annealing process effects on the concerned parameters and, therefore, the above-mentioned measurements were repeated again. The films exhibited reasonable optical transmittance and electrical conductivity and greatly improved after annealing. The characterization was focused on the scanning of the film surfaces before and after annealing, which has a prominent effect on the optical properties of the films. Film surfaces were scanned by scanning probe microscopy in contact atomic force mode. The most consideration was devoted to image analysis.     

Electrical and optical properties of ZnO thin film as a function of deposition parameters

Al-doped zinc oxide (AZO) and undoped zinc oxide (ZO) films have been prepared by rf magnetron sputtering. Films with low resistivities were achieved by using an Al-doped ZnO target and films with higher resistivities can be obtained by introducing oxygen during deposition. An AZO thin film which was fabricated with an rf power of 180 W, a sputtering pressure of 10 mTorr and thickness of 5000 Å showed the lowest resistivity of 1.4×10⁻⁴ Ω cm and transmittance of 95% in the visible range, and ZO film made by reactive sputtering with the above 10% oxygen content had the highest resistivity of 6×10¹⁴ Ω cm.     

Discharge power dependence of structural, optical and electrical properties of DC sputtered antimony doped tin oxide (ATO) films

Antimony doped tin oxide (ATO) is a transparent conducting oxide (TCO), which has been the focus of intensified study due to its wide range of technological applications and low cost. In the present work ATO films have been prepared by reactive DC magnetron sputtering from a metallic target at different discharge power densities without direct substrate heating. Then a post-deposition annealing at 350 °C in N₂ during 20 min was performed. There is a process window for the optimal sputter deposition of ATO with a minimum resistivity of about 3.3×10⁻³ Ω cm observed in samples deposited at a power density of 1.13 W/cm². These samples, which present a (2 1 1) preferential orientation, have good electrical conductivity and good transparency in the visible range. Higher values of sputtering discharge power density (1.24 W/cm²) change the preferential orientation to (1 0 1) because of the formation of oxygen vacancy planes. These samples are less conductive and transparent because their layered structure reduces the free charge mobility and allows the formation of Sb in its unusual oxidation state 4+ (between Sb³⁺ and Sb⁵⁺), which produces a sample blue darkening. Higher discharge power densities, above 1.41 W/cm², produce amorphous samples and an abrupt resistivity increase. The aim of the present work is to go into more depth in the knowledge of ATO in order to develop thin films with optimal electrical and optical properties.     

Combining Bayesian Networks and Total Cost of Ownership method for supplier selection analysis

In this study, we analyze the supplier selection process by combining Bayesian Networks (BN) and Total Cost of Ownership (TCO) methods. The proposed approach aims to efficiently incorporate and exploit the buyer’s domain-specific information when the buyer has both limited and uncertain information regarding the supplier. This study examines uncertainty from a total cost perspective, with regards to causes of supplier performance and capability on buyer’s organization. The proposed approach is assessed and tested in automotive industry for tier-1 supplier for selecting its own suppliers. To efficiently facilitate expert opinions, we form factors to represent and explain various supplier selection criteria and to reduce complexity. The case study in automotive industry shows several advantages of the proposed method. A BN approach facilitates a more insightful evaluation and selection of alternatives given its semantics for decision making. The buyer can also make an accurate cost estimation that are specifically linked with suppliers’ performance. Both buyer and supplier have clear vision to reduce costs and to improve the relations.