Molecular Analysis of the Mechanical Behavior of Plasticized Amorphous Polymer

Plasticization effects on the mechanical behavior were investigated on two families of materials based on poly(methyl methacrylate) (PMMA) and poly(vinyl chloride) (PVC), respectively. For this purpose, PMMA was blended with poly(vinylidene fluoride) (PVDF) by co-precipitation from solution, all over the PVDF range 0-40 wt% where the samples remain amorphous. Di-octylphtalate (DOP) was mechanically dispersed in PVC over the DOP range 0-20 wt%. The relaxation behavior of the samples was studied by differential scanning calorimetry at heating rate of 10 °C$\cdot$min-1 and by dynamic mechanical analysis at the frequency 1 Hz over the temperature range $-100~^{\circ}$C/150 °C. Stress strain curves were recorded during compression testing at a deformation rate of 2.10-3 s-1. Data analysis was carried out on the molecular scale; it permitted to highlight the influence of the β elaxation motions on the plastic behavior. Consideration of the non elastic part of the energy to yield was clearly related to the contribution of $\alpha$ and $\beta$ motions

Antimony sulphide, an absorber layer for solar cell application

Replacement of the toxic, expensive and scarce materials with nontoxic, cheap and earth-abundant one, in solar cell absorber layer, is immensely needed to realize the vision of green and sustainable energy. Two-micrometre-thin antimony sulphide film is considered to be adequate as an absorbing layer in solar cell applications. In this paper, we synthesize antimony sulphide thin films on glass substrate by physical vapour deposition technique, and the obtained films were then annealed at different temperatures (150–250 °C). The as-deposited and annealed samples were investigated for structural and optoelectronic properties using different characterization techniques. The X-ray diffraction analysis showed that the annealed samples were polycrystalline with Sb2S3 phase, while the as-deposited sample was amorphous in nature. The optical properties are measured via optical ellipsometric techniques. The measured absorbance of the film is adequately high, and every photon is found to be absorbed in visible and NIR range. The conductivity type of the films measured by hot-point probe technique is determined to be p-type. The optical band gap of the resulted samples was in the range (2.4–1.3 eV) for the as-deposited and annealed films