Band gap engineering of (N,Ta)-codoped TiO2: A first-principles calculation

Band structure engineering of TiO2 from first-principles calculations

Band gap engineering of FeS2 under biaxial strain: a first principles study.

The promising photovoltaic activity of pyrite (FeS2) is attributed to its excellent optical absorptivity and earth abundance, but its band gap, 0.95 eV, is slightly lower than the optimum value of 1.3 eV. Here we report the first investigation of strained FeS2, whose band gap can be increased by ∼0.3 eV. The influence of uniaxial and biaxial strains on the atomic structure as well as the electr...

First principles elaboration of low band gap ladder-type polymers.

Ladder-type polymers, obtained by small modifications of the atomic structure of ladder-type polythiophene, are studied using density-functional theory calculations. Within the local-density and GW approximations, it is found that upon a simple substitution of the sulfur atoms by nitrogen and boron atoms, the band structure of the resulting polymer exhibits band overlap between the occupied and...

Non-Band-Gap Photoexcitation of Hydroxylated TiO2

The photochemistry of TiO2 has been studied intensively since it was discovered that TiO2 can act as a photocatalyst. Nevertheless, it has proven difficult to establish the detailed charge-transfer processes involved, partly because the excited states involved are difficult to study. Here we present evidence of the existence of hydroxyl-induced excited states in the conduction band region. Usin...

Degradation of Phthalocyanine by a Core-Shell TiO2 Photocatalyst: Effect of Iron Dopping on Band Gap

In this research, initially, the sol-gel method was employed to produce γ-alumina and TiO2 catalysts with core-shell structure. Iron (III) was used as a dopant. The newlyproduced core-shells were Fe/TiO2// Fe/ γ-Al2O3 (FTFA). Sulfonated cobalt phthalocyanine was used as a dye pollutant in Merox process. By doping Fe in TiO2 catalyst, the ef...