Insight DFT studies about the optoelectronic properties of Fe and Ga doped Mg-based hydrides: Efficient materials for optical devices

We reported and discussed results for the first time for the electronic and optical properties of Fe doped MgH2 and Ga doped MgH2Fe hydride materials by first-principles calculations using generalized gradient approximation (GGA) within the density functional theory (DFT). The effective contributions of various electronic bands and density of states calculations confirms a quite weak bonding nature between Fe, Mg and H atoms in Fe doped MgH2 system. Also, the addition of Ga, the interaction between Mg and H atoms show weak bonding along with extensive reduction in the PDOS of both Mg and H atoms closer to Fermi level. The optical properties such as dielectric function, refractive index, extinction coefficient, absorption, reflectivity spectra, electron energy loss function and the real part of optical conductivity were calculated and discussed in detail. The observed sharp energy loss peak values for both the studied systems match up with the edge of plasma energy and corresponds to plasma frequency which indicates transition between semiconductor and dielectric characters. The base for the absorption was discussed in detail in addition to observed spectral peaks on the basis of their electronic band structures and crystal field nature.