Khaled Alouani

Electrolytic Manganese Dioxide Coatings on High Aspect Ratio Micro-Pillar Arrays for 3D Thin Film Lithium Ion Batteries

In this work, we present the electrochemical deposition of manganese dioxide (MnO2) thin films on carbon-coated TiN/Si micro-pillars. The carbon buffer layer, grown by plasma enhanced chemical vapor deposition (PECVD), is used as a protective coating for the underlying TiN current collector from oxidation, during the film deposition, while improving the electrical conductivity of the stack. A conformal electrolytic MnO2 (EMD) coating is successfully achieved on high aspect ratio C/TiN/Si pillar arrays by tailoring the deposition process. Lithiation/Delithiation cycling tests have been performed. Reversible insertion and extraction of Li+ through EMD structure are observed. The fabricated stack is thus considered as a good candidate not only for 3D micorbatteries but also for other energy storage applications.

Structural and optical properties of tin (II) sulfide thin films deposited using organophosphorus precursor (Ph3PS)

Tin sulfide (SnS) thin films have been deposited onto glass substrates using triphenylphosphine sulfide (Ph3PS) as a sulfur precursor in a chemical vapor deposition reactor in a temperature range of 250 °C–400 °C. The influence of the sulphidisation temperature in the crystal structure, surface morphology, chemical composition and optical properties has been investigated. X-ray diffraction, energy dispersive analysis of x-rays, and Raman spectroscopy showed that pure SnS thin films have been successfully obtained at 250 °C. All the deposited films were polycrystalline and showed orthorhombic structure, with a preferential orientation according to the direction 〈111〉. The optical measurements showed that the films deposited exhibited a direct allowed transition and have a relatively high absorption coefficient. The presence of mixed tin sulfide phases granted by the variation of the sulphidisation temperature has affected the optical properties of the deposited films. The refractive index (n) and extinction coefficient (k), has low values compared to conventional semiconductor materials. The grown films can be considered as a good light absorbing material and a promising candidate for application in optoelectronic devices.

Crystal structure and Hirshfeld surface analysis of the new cyclo­diphosphazane [EtNP(S)NMe2]2

A new cyclodiphosphazane, [EtNP(S)NMe2]2, was synthesized and characterized by NMR and EDX spectroscopy and single-crystal XRD. The stability of the structure is ensured only by van der Waals interactions and the their prevalence is confirmed by an analysis of the three-dimensional Hirshfeld surface (HS) and two-dimensional fingerprint plots (FP).