A DFT study of BeX (X = S, Se, Te) semiconductor: modified Becke Johnson (mBJ) potential

The electronic, optical and elastic properties of BeX were performed within full potential liberalized augmented plane wave method based on density functional theory (DFT). Generalized gradient approximation (GGA) and modified Becke Johnson (TB-mBJ) potential were used for exchange correlation. The mBJ gives improved band gap as compare to GGA and in close agreement with the experimental results. The present band gaps of BeS, BeSe and BeTe calculated within mBJ are 4.40, 4.0 and 2.40 eV respectively.