Abdallah El Kenz

New transparent conducting oxide based on doped SnO 2 for solar cells

The full-potential linearized augmented plane wave method (FP-LAPW) based on the density functional theory (DFT) and Boltzmanns Transport theory, are employed to investigate theoretically the electronic structure, optical and electrical properties of Sc, Ti and V doped rutile SnO2. The FP-LAPW based on the new potential approximation known as the Tran-Blaha modified Becke-Johnson exchange potential approximation (mBJ). The calculated band structure and density of states (DOS) exhibit a band gap of pure SnO2 (3.3 eV) closer to the experimental one. As well, our results indicate that the average transmittance in the 400 to 1000 nm wavelength region was 90%. The high transmittance and electrical conductivity indicate that doped SnO2 system is a potential as material for solar energy applications.

Hydrogen diffusion in the magnesium titanium hydrides

The diffusion of hydrogen in the rutile and fluorite structures of the magnesium titanium hydrides Mg1−xTixH2 is studied using first-principles density functional theory. We compare the vacancy formation, the diffusion and the binding energy in both structures for x=0.125 and x=0.25 concentrations. Our results confirm that the enhancement of the diffusion is mainly due to the structural change, where we find that the activation barriers are lower in the fluorite structure compared to that of the rutile structure. We also find that the hydrogen atoms tend to bind with each other in the rutile structure by finding an important negative binding energy compared to the fluorite structure.