First-principles quantum computational study to investigate radiation energy-dependent effect on optoelectronic properties of bismuth oxyhalides BiOX (X= I, Br)

Metal oxyhalides are potential candidates for fundamental and technological interest in pharmaceutical, biological, optical, photoluminance, sensing, energy, and photocatalyst applications. In this study, using first-principles density functional quantum computational approach, we investigate the electronic and optical properties of two members of bismuth oxyhalides, BiOX (X = I, Br). The study is mainly aimed to characterize and examine the light radiation energy-dependent optical properties of the compounds by using mBJ desnty functional with the full potential linearized augmented plane wave method. The oxyhalides show indirect bandgap semiconductor nature having bandgaps of 2.2 eV for BiOI and 3.5 eV for BiOBr. Besides, these are p-type materials owing to a large hole-like carrier density of states in the valence bands close to the Fermi level. The energy bands show considerable dispersion of particles. The increasing reflectivity at high light energy shows the potential of the materials as good reflectors in shielding screens or glasses to avoid damage from the ultraviolet radiation. •First-principles quantum computational analysis on optoelectronic properties of BiOI and BiOBr via mBJ method.•We predict that BiOI & BiOBr are p-type semiconductors.•The calculated indirect band gap is 2.2 eV for BiOI and 3.5 eV for BiOBr.•Optical properties include dielectric function, reflectivity, refractive index, absorption, energy loss function.•Results may find basic & applied applications in medical, nuclear reactors, catalysts, lighting, and energy technology.