Structural, Electronic, and Optical Properties of Superhard Materials tP10-FeB4 and I4 1 /acd-FeB4

The geometrical, electronic, and optical properties of superhard structures tP10-FeB4 and I4 1 /acd-FeB4 have been investigated using different density functional theory (DFT) approaches. The geometrical and electronic properties were calculated using DFT with projector augmented wave pseudopotentials. To obtain reasonable fundamental bandgaps and optical properties, we performed post-DFT calculations by solving the Bethe–Salpeter equation (BSE) based on Green’s function calculations. The absorption, reflectivity, refractivity, and photoconductivity were calculated, analyzed, and compared with results available in literature. The results of the BSE method show that the optical properties of both the tP10-FeB4 and I4 1 /acd-FeB4 structures demonstrate several novel characteristics, implying they are potential optical materials with various applications.