X-ray Diffraction Study Of Thin Films Research Articles

Solution-Processable Organic Photovoltaic Cell Based on the Oligothiophene with Solubilizing β-alkyl Groups

We synthesized a linear π-conjugated small molecule (β-DH5T) based on thiophene, using the palladium-catalyzed Suzuki coupling. The oligothiophene was designed to contain β-substituted solubilizing alkyl groups to facilitate solution processing. The organic photovoltaic cell based on β-DH5T:PC71BM gave a power conversion efficiency of 0.46% with a short-circuit current of 4.69 mA/cm2, an open-circuit voltage of 0.60 V, and a fill factor of 0.35, giving under AM 1.5G illumination (100 mW/cm2). The optical and electrochemical properties and molecular alignment of oligothiophene were investigated using UV-visible absorption spectroscopy, cyclic voltammetry, and thin-film X-ray diffraction studies.

In vitro bioactivity and corrosion resistance of Zr incorporated TiO2 nanotube arrays for orthopaedic applications

The present investigation deals with the incorporation of zirconium (Zr) ions onto TiO2 nanotube arrays (TNT) by simple dip coating method for biomedical implants. The electrochemical behaviour of the specimens were studied with potentiodynamic polarization (Tafel plots) and electrochemical impedance spectroscopy (EIS), while surface analysis involved field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), attenuated total reflectance fourier transform infrared (ATR-FTIR) spectroscopy, thin film x-ray diffraction (TF-XRD) and contact angle measurements. The FE-SEM morphology revealed that self-organised TNT was tightly arrayed with an average diameter of 110±4nm. The wall thickness and length of 15±2nm and 2.1±0.3μm respectively were developed by electrochemical anodization of titanium sheet in a mixture of ethylene glycol and NH4F electrolyte. The EDS, ATR-FTIR and TF-XRD studies were revealed the incorporation of Zr onto TNT specimens. Hydroxyapatite (HAp) was grown over Zr ions incorporated TNT (Zr-TNT) via in vitro immersion method. The HAp grown Zr-TNT exhibited higher bioactivity as well as enhanced corrosion resistance when compared to other specimen. Hence, Zr-TNT could be a viable material for the use as orthopaedic implant with good bioactivity and corrosion resistance.

Electronic Properties-Morphology Correlation of a Rod–Rod Semiconducting Liquid Crystalline Block Copolymer Containing Poly(3-hexylthiophene)

The influence of the solvent and annealing temperature on the field-effect mobilities and morphologies of poly(3-hexylthiophene)-b-poly(γ-benzyl-L-glutamate) (P3HT-b-PBLG) rod-rod diblock copolymer has been investigated. Thin film X-ray diffraction studies show peaks originating from both P3HT and PBLG indicating that the crystalline nature of both the blocks is conserved after the formation of the block copolymer. It has been observed that the field-effect mobilities of the diblock copolymer are independent of the annealing temperatures for thin films deposited from both 1,2,4-trichlorobenzene and chloroform solvents. The correlation between the field-effect mobility and morphology indicates that the P3HT block self-assembles at the surface SiO(2) dielectric.

Resistivity and structural defects of reactively sputtered TiN and HfN films

TiN and HfN thin films have been deposited by reactive r.f.-sputtering in an Ar-N 2 gas mixture under different condition of total gas pressure ( P T ) from 0.7 Pa to 5.3 Pa. Thin film X-ray diffraction studies show that the structure of the TiN films is gradually changed from TiN f.c.c. structure to amorphous with increasing P T . On the other hand, HfN f.c.c. structure with a strong (111)-preferred orientation is formed for all HfN films prepared with various P T . The resistivity of the films at room temperature ( ϱ rt ) increased with increasing P T in different ways between TiN and HfN. The films with ϱ rt ≤ 0.3 mΩm show √T dependence in conductivity at low temperature. HfN films with ϱ rt = 1.6 mΩm, the largest one measured, show an insulating behavior. The magnetoconductance Δσ(H) measurements showed that the spinorbit coupling of HfN is found to be stronger than that of TiN.

Microstructure and Optical Properties of Aluminum Nitride Thin Films

AbstractPolycrystalline aluminum nitride (AIN) thin films have been synthesized by ion-beam assisted deposition method and the effect of ion beam energy on the film structure and optical properties has been studied. The kinetic energy of nitrogen ion beam was varied from 0.05 to 1.5 keV under the constant current density. Microstructure of films was examined by thin film X ray diffraction (TFXRD) and optical transmission spectrum from 220 to 2200 nm was measured by UV-visible spectrometer. The TFXRD studies show that the (00*02) plane of hexagonal AIN grows preferentially with the ion beam energy of 0.05 keV and the intensity of the (10*0) and (10*1) planes becomes strong with increasing the ion beam energy. The optical measurements reveal that the wavy structures due to the interference effect are observed in the transmission spectra and the wavy pattern decreases with increasing the ion beam energy, resulting in the decrease of refractive index.

The study of diffusion of copper in thin films of silver and AgAl alloys as a function of increasing aluminium concentration

The diffusion of copper through electron-beam-evaporated silver and AgAl alloy thin films of four different compositions (5.8, 9.2, 15.8 and 18.2 at % Al) has been studied by monitoring the electrical resistance with time in the temperature range 343–543 K. The aim of this work is to determine the extent to which the presence of aluminium affects copper diffusion through silver thin films. It is found that the activation energy Q and the pre-exponential factor D 0 determined from the Arrhenius plot decrease in the aluminium content in the alloy film but as a whole the diffusion coefficient increases with increasing aluminium content in the temperature range of interest. Transmission electron microscopy and thin film X-ray diffraction studies with 9.2 and 18.2 at.% Al alloy films indicate that the microstructures and corresponding selected-area diffraction pattern vary as a function of aluminium content. With the addition of aluminium, copper reacts to form Al 2 Cu (θ phase) precipitates even at room temperature. Precipitation probably occurs along the grain boundaries of copper and along the alloy-Cu interface, thereby reducing grain growth, but, on annealing such films, this retarding effect of the precipitates on the grain growth is removed. The cause of enhancement of diffusion coefficient with increased aluminium content is attributed to the fact that the concentration gradient and accompanying stress gradient at the interface and grain boundaries produce dislocations.