Electronic structure and optical properties of lithium tetraborate detector calculated using semi-local exchange correlation potential

Ab-initio calculations based on density functional theory have been employed to study electronic and optical properties of lithium tetraborate (Li2B4O7) detector. Exchange–correlation (XC) effects were simulated by recently developed modified Becke–Johnson (mBJ) potential. It is demonstrated that this, computationally efficient semi-local potential, correctly describes band gap, electron bands and optical properties of the compound. This fact excludes necessity of using hybrid XC potentials in the future theoretical investigations of defects in Li2B4O7. Calculated optical response is found to be anisotropic in near ultraviolet region, with a threshold absorption peak dominated by electron transitions within a trigonal boron-oxygen structure motif.