Preparation of cobalt–titanium dioxide nanocomposite films by combining inverse micelle method and plasma treatment

We investigated the processing of a metal nanogranular thin film of Co–Ti–O system by combining a colloidal wet process (inverse micelle method) and a dry process (plasma treatment). Both TEM and EDS analyses revealed that the film was prepared along with suppression of metal cobalt nanoparticles' oxidization. Results showed that plasma processing provides new possibilities for processing of materials that are difficult to prepare under equilibrium conditions.     

空间太阳电池玻璃盖板表面超薄ITO防静电层的设计及制备工艺

ITO/MgF2复合薄膜既具有较好的表面导电性能又具有较高的透过率,可应用于空间太阳电池玻璃盖板表面。文章主要对ITO/MgF2复合薄膜中表层的超薄ITO薄膜进行了研究。利用TFCalc软件模拟了ITO薄膜厚度对ITO/MgF2复合薄膜光学性能的影响,根据模拟结果采用电子束蒸发法在衬底上依次沉积MgF2薄膜和氧化铟锡(ITO)薄膜,研究了ITO薄膜工艺参数(沉积速率、沉积温度和工作气压)和ITO薄膜厚度对ITO/MgF2复合薄膜光电性能及微观结构的影响。当ITO薄膜沉积速率为0.05nm/s、沉积温度为400℃、工作气压为2.3×10~(-2) Pa、厚度为10nm时,表层ITO薄膜基本连续,其方块电阻(1.94kΩ/)已符合设计需求,ITO/MgF2复合薄膜在可见光区间(400~800nm)的平均透过率达到89.00%。     

Doping-free fabrication of silicon thin films for schottky solar cell

Thin film Schottky solar cells were fabricated without doping processes, which may provide an alternative approach to the conventional thin film solar cells in the n-i-p configuration. A thin Co layer was coated on a substrate, which worked as a back contact metal and then Si film was grown above it. Deposition condition may modulate the Si film structure to be a fully amorphous Si (a-Si) or a mixing of microcrystalline Si (mc-Si) and a-Si. A thin Au layer was deposited above the grown Si films, which formed a Schottky junction. Two types of Schottky solar cells were prepared on a fully a-Si film and a mixing of mc-Si and a-Si film. Under one sun illumination, the mixing of mc-Si and a-Si device provided 35% and 68.4% enhancement in the open circuit voltage and fill factor compared to that of the amorphous device.     

Preventing Thin Film Dewetting via Graphene Capping

A monolayer 2D capping layer with high Young's modulus is shown to be able to effectively suppress the dewetting of underlying thin films of small organic semiconductor molecule, polymer, and polycrystalline metal, respectively. To verify the universality of this capping layer approach, the dewetting experiments are performed for single‐layer graphene transferred onto polystyrene (PS), semiconducting thienoazacoronene (EH‐TAC), gold, and also MoS₂ on PS. Thermodynamic modeling indicates that the exceptionally high Young's modulus and surface conformity of 2D capping layers such as graphene and MoS₂ substantially suppress surface fluctuations and thus dewetting. As long as the uncovered area is smaller than the fluctuation wavelength of the thin film in a dewetting process via spinodal decomposition, the dewetting should be suppressed. The 2D monolayer‐capping approach opens up exciting new possibilities to enhance the thermal stability and expands the processing parameters for thin film materials without significantly altering their physical properties.     

Effects of transition metal (Cu,Zn, Mn) doped on leakage current and ferroelectric properties of BiFeO<Subscript>3</Subscript> thin films

BiFeO₃ (BFO) and transition metal (Cu, Zn, Mn) doped BFO thin films were successfully fabricated on indium tin oxide (ITO)/glass substrate using sol–gel process, spin coating and layer by layer technique. Compared to the pure BFO thin film, improved ferroelectric and leakage current properties were observed in the transition metal doped BFO thin films. The transition metal (Cu, Zn, Mn) doped BFO thin films have varying degrees of lower leakage current compared with the pure BFO film. The substitution of Cu and Zn increase the remnant polarization of BFO thin films. The values of remnant polarization (2Pr) were 120.6 and 126.7 μC/cm² at 933 kV/cm for Cu-doped and Zn-doped BFO thin film, respectively.     

Properties of anodic oxides grown on a hafnium–tantalum–titanium thin film library

A ternary thin film combinatorial materials library of the valve metal system Hf–Ta–Ti obtained by co-sputtering was studied. The microstructural and crystallographic analysis of the obtained compositions revealed a crystalline and textured surface, with the exception of compositions with Ta concentration above 48 at.% which are amorphous and show a flat surface. Electrochemical anodization of the composition spread thin films was used for analysing the growth of the mixed surface oxides. Oxide formation factors, obtained from the potentiodynamic anodization curves, as well as the dielectric constants and electrical resistances, obtained from electrochemical impedance spectroscopy, were mapped along two dimensions of the library using a scanning droplet cell microscope. The semiconducting properties of the anodic oxides were mapped using Mott–Schottky analysis. The degree of oxide mixing was analysed qualitatively using x-ray photoelectron spectroscopy depth profiling. A quantitative analysis of the surface oxides was performed and correlated to the as-deposited metal thin film compositions. In the concurrent transport of the three metal cations during oxide growth a clear speed order of Ti > Hf > Ta was proven.     

One‐Step Solution Phase Growth of Transition Metal Dichalcogenide Thin Films Directly on Solid Substrates

Ultrathin transition metal dichalcogenides (TMDs) have exotic electronic properties. With success in easy synthesis of high quality TMD thin films, the potential applications will become more viable in electronics, optics, energy storage, and catalysis. Synthesis of TMD thin films has been mostly performed in vacuum or by thermolysis. So far, there is no solution phase synthesis to produce large‐area thin films directly on target substrates. Here, this paper reports a one‐step quick synthesis (within 45–90 s) of TMD thin films (MoS₂, WS₂, MoSe₂, WSe₂, etc.) on solid substrates by using microwave irradiation on a precursor‐containing electrolyte solution. The numbers of the quintuple layers of the TMD thin films are precisely controllable by varying the precursor's concentration in the electrolyte solution. A photodetector made of MoS₂ thin film comprising of small size grains shows near‐IR absorption, supported by the first principle calculation, exhibits a high photoresponsivity (>300 mA W^?1) and a fast response (124 µs). This study paves a robust way for the synthesis of various TMD thin films in solution phases.     

ZnO nanostructure thin films by continuous spray pyrolysis using doped precursor for Si solar cell application

This work presents deposition of Zn solution seed layer assisted growth of zinc oxide (ZnO) nanostructure layers by continuous spray pyrolysis reactor using lanthanides (Er and Eu) and metal (Al) influenced zinc acetate precursor solution. Dopants in precursors have influenced structural property, surface morphology and optical reflectance of resulting ZnO thin films which are supported by X-ray diffractometer, scanning electron microscope and reflectance measurements. Enhanced dispersion amongst nanorods is observed under the influence of Er and Al dopant in ZnO thin film. The change of precursor from Zinc acetate to Titanium tetraisopropoxide for Er doped precursor is helping to achieve better crystalline ZnO nanorods arrangement with increased homogenous growth, which results into improved light reflectance reduction of thin film. The experimental evidences of light reflectance from ZnO nanorods on Si surface is studied with the help of FDTD based Lumerical software package which can be a useful study for designing ZnO nanorods thin film in device purposes. The utility of ZnO layer by this reactor on low efficiency Si solar cell is also explored in improving device efficiency via increase of photocurrent.     

Single-step formation of a graphene-metal hybrid transparent and electrically conductive film

We report here a rapid (10 s of heating) graphene growth method that can be carried out on any desired substrate, including an insulator, thus negating the need for the transfer from the metal substrate. This technique is based on metal-induced crystallization of amorphous carbon (a-C) to graphene, and involves an ultra-thin metal layer that is less than 10 nm in thickness. Rapid annealing of a bilayer of a-C and metal deposited on the surface leads to the formation of graphene film, and to subsequent breaking-up of the thin metal layer underneath the film, thus resulting in the formation of a graphene–metal hybrid film which is both transparent and electrically conducting. Based on Raman studies, we have also systematically compared ultra-thin metal-induced crystallization behavior with a case of conventional thick metal. Based on the present investigation, it was observed that the dominant growth mechanism in ultra-thin metal-induced crystallization is nucleation controlled.     

Fabrication and characterization of direct patterning ferroelectric Sr0.9Bi2.1Ta2O9 thin films by photosensitive sol–gel solution

Photosensitive ferroelectric Sr_0.9Bi_2.1Ta₂O₉ (SBT) precursor solutions were synthesized using strontium ethoxide chelated with ethylacetoacetone, tetramethylheptanedionato bismuth and tantalum ethoxide chelated with ethylacetoacetone. SBT thin films with 200 nm thickness were prepared on Pt/TiO₂/SiO₂/Si substrates using the spin coating method. As UV light exposure time to the SBT thin film increased, the intensity of the UV absorption peak of the metal β-diketonate decreased due to metal–oxygen–metal bond formation, which led to decreased solubility of SBT thin film. The solubility difference enabled direct patterning of thin films that had ferroelectric properties. The ferroelectric properties of the UV irradiated SBT thin films were superior to those of the non-UV irradiated films. Pr/Ps and 2 Pr values (at 3 V) of SBT thin films improved approximately 8% and 5%, respectively, with UV irradiation.     

HFCVD grown graphene like carbon–nickel nanocomposite thin film as effective counter electrode for dye sensitized solar cells

The two step processes of hot filament chemical vapor deposition (HFCVD) and DC sputtering were used to grow graphene like carbon (GLC)–nickel (Ni) nanocomposite thin film on fluorine-doped tin oxide (FTO) glass and applied as counter electrode (CE) for dye sensitized solar cells (DSSCs). The morphological and absorption properties revealed uniform GLC–Ni thin film with reasonable transmittance. The GLC–Ni thin film showed enhanced electrical conductivity as compared to FTO. The good electrocatalytic activity towards iodide ions in redox electrolyte was showed by the prepared GLC–Ni/FTO thin film electrode. The fabricated DSSC with GLC–Ni/FTO counter electrode (CE) presented relatively moderate solar-to-electrical conversion efficiency of ∼3.1% with high short-circuit current density (J_SC) of ∼10.03 mA/cm², open circuit voltage (V_OC) of ∼0.663 V with fill factor (FF) of ∼0.45, which might attribute to enhanced electrical conductivity and the electrocatalytic activity of GLC–Ni/FTO CE.     

Study of the Electron–Phonon Relaxation in Thin Metal Films Using Transient Thermoreflectance Technique

Electron–phonon (e–ph) relaxation in thin metal films is an important consideration in many ultra-small and ultra-fast applications. In this work, e–ph relaxation in thin gold and aluminum films has been studied using the transient thermoreflectance technique which is demonstrated sensitive enough to study the relaxation process. The optical properties of the thin metal films are different from those of bulk metal and have been measured. Based on confirmation of the measurements, the effects of metal type, film thickness, and interface on e–ph relaxation have been experimentally studied. The thermoreflectance traces of gold and aluminum films have been compared. The results show that the e–ph relaxation and the effect of electron and lattice temperatures on the thermoreflectance of gold and aluminum are quite different. The e–ph relaxation is independent of film thickness and interface.     

Atomic Layer Deposition

Atomic layer deposition, ALd, is a thin film deposition technology that enables new and highly competitive products. As a disruptive technology, it can often replace existing production technology and improve throughput, coating quality and sometimes process sustainability. ALd is also a powerful resource for advanced nanotechnology research. Today's industrial applications of ALd habitually address a concrete requirement to manufacture precise nanometer–thick, dense and pinhole–free conformal thin films of exact chemical composition on various shapes and geometries. For today's businesses, ALd and Beneq offer the necessary tools to enable growth, by means of new and innovative applications, reliable production equipment and attractive cost of ownership.     

Low-temperature processable Sn-doped ZnO films as electron transporting layers for perovskite solar cells

Charge-transporting processable layers at a low temperature is a challenge for fabricating novel, highly stable and flexible optoelectronic devices. In fact, the crystallization of metal oxide usually needs to be processed under a high-temperature to obtain excellent semiconducting properties. In this work, Sn-doped ZnO (TZO) thin films, as electron transporting layers (ETLs) in perovskite solar cells, were prepared via sol–gel method at a temperature of less than 180 °C. The effects of annealing temperature on the properties of TZO thin films were investigated. It was found that the electrical properties of the TZO films were improved with increasing annealing temperature. In addition, an elemental composition analysis revealed that a temperature of only 140 °C sufficed for converting the precursor gel film into TZO film. The perovskite solar cell, which utilized a low-temperature TZO thin film, yielded a better power conversion efficiency than one with high-temperature ETLs (180 °C). These results imply that discovering low-temperature ETL processing for sol–gel enables good-quality metal oxide ETL, which can also be used in flexible solar cell applications.

     

Transparente und leitfähige Veredelung von Kunststoffoberflächen

Deposition Techniques for Transparent Conducting Thin‐Films on Glass and Polymer Substrates We report on thin films deposited at atmospheric pressures on glass and polymer substrates with various techniques. The introduced thin‐film materials show intrinsic properties being suitable for different applications while maintaining the principle properties of the substrates themselves (e. g. shape. rigidity/flexibility, transparency). With the main focus on optical and electronic applications the properties of the deposited films can be adjusted by the choice of coating material (e. g. metal oxide, CNT), the film's shape (compact, particulate) and the deposition process itself. We compare deposition and properties of different TCO‐materials with CNT‐based thin film techniques and demonstrate approaches for the integration of these processes in production lines.     

Plasma enhanced germanium nitride dielectric thin films for phase-change recording systems

The more efficient dielectric material and structure have been developed for fast phase-change optical recording systems. The germanium nitride thin film was reactively sputtered using a d.c. chamber, operated at 3 kW with a mixed gas plasma of argon and nitrogen. The dielectric thin film of 11–13 nm has been designed as the upper dielectric layer between the Ge–In–Sb–Te active layer and the silver reflective layer. The optical storage disks were initialized by a Hitachi POP120-8E device to provide crystalline active layers before the dynamic tests. The initialization was conducted using 810 nm laser at 2300 mW while the disks were rotated at a constant linear velocity of 10 m/s. The optical properties were analyzed using a Steag ETA-RT optical measuring system at 410–1010 nm wavelength. The power margin window was shown to be effectively improved by 60% to 18–26 mW when compared with the traditional ZnS–SiO₂ dielectric system. TEM (transmission electron microscope) micrograph showed clear profile for the standard 3T laser marks on the active layer. The plasma enhanced germanium nitride dielectric thin film could improve digital versatile disk's (DVD) production yield and efficiency.     

复合光导层液晶光阀的研究

介绍了一种具有柱状结构的a-Si：H／nc—Si复合光导层的液晶光阀，复合光导层是通过热蒸发和等离子体辉光放电沉积方法，采用Al诱导a-Si：H制成的。经过测试，这种柱状结构薄膜具有电导各向异性，其横向电导率小于纵向电导率。用这种薄膜制成的液晶光阀其分辨率达到5001p／inch。     

Transparent with wide band gap InZnO nano thin film: Preparation and characterizations

Novel indium zinc oxide (InZnO) thin film of 100 nm thickness was prepared onto pre-cleaned glass plate by thermal evaporation technique from InZnO nanoparticles. The metal oxide (In–O and Zn–O) bond and In, Zn and O elements present in the films were confirmed by Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy. The X-ray diffraction patterns revealed the mixed phase of cubic In₂O₃ and wurzite-hexagonal ZnO structure. SEM images showed smooth surface with uniform distribution of grains (201–240 nm) over the entire film surface. High transparency and low absorption obtained from optical study. The band gap energy was evaluated to be about 3.46–3.55 eV by Tauc’s plot. The structure, smooth surface and high transparency with wide band gap energy lead the thermally evaporated InZnO nano thin film to be used for transparent layer in optoelectronic devices in the future.     

SERS Active Surface in Two Steps,Patterning and Metallization

Robust and reproducible metallized nano/microstructured surfaces of polymeric surfaces have been successfully prepared by direct laser interference patterning (DLIP) of commercial polymeric films followed by sputtering of metallic thin films. The SERS spectra for 2‐thioaniline adsorbed on a structured polycarbonate surfaces covered with a gold or platinum film showed a ca. three order of magnitude enhancement over a flat surface with the same metal film. The method here reported is suitable for mass production of substrates for SERS since large areas (several cm²) can be structured in ca. 1–5 s.     

Application of novel azo metal thin film in optical recording

The absorption spectrum of spin-coated azo metal thin film showed a comparatively large absorption band in the wavelength region (500–600 nm), which matched with the wavelength of the GaAlInP semiconductor diode laser (630–650 nm). The optical recording performance of the film was investigated.