Structural, electronic and optical properties of chromium carbide (Cr3C) as potential counter electrode material: a first principle study

Transition metal carbides are recently considered to be potential substitutes to platinum counter electrode due to their low cost, high catalytic activity and good thermal stability. In this paper, we investigate the structural, electronics, and optical properties of one of the transition metal carbides (Cr3C). The structural and electronic properties were computed using the first principles approach, a generalized gradient approximation (PBE-GGA) as exchange correlation functional within density functional theory (DFT) was used for the calculations. The optimized lattice parameters of the compound were = 4.525 Ǻ, = 5.186 Ǻ, = 6.659 Ǻ and ∝ = β = γ = 90.00which are in agreement with number of theoretical and experimental results. The calculated band gap and density of state (DOS) of this compound reveals the presence of Valence Band Maximum (VBM) and Conduction Band Minimum (CBM) at different symmetry point with the intersection of several energy bands crossing the Fermi level, this interaction indicate a metallicity nature and may cost the conductive nature of the material to have sufficient electro-catalytic ability for the reduction of I3- ions in counter electrode of DSSCs. The optical properties are calculated from the spectra of dielectric function alongside with the other related optical properties like energy loss function, reflectivity, refractive index, extinction coefficient and conductivity within a continuous energy range of 0 to 16eV. The obtained results of the optical properties of this material show that the materials can be use as possible candidates for counter electrode of DSSC.