PHASE STABILITY, ELECTRONIC AND OPTICAL BEHAVIOR OF PbS, PbSe AND PbTe COMPOUNDS

Abstract

Ab initio calculations based on density functional theory using the full potential linearized augmented plane wave method (FP-LAPW) have been carried out to find the structural stability of different crystallographic phases, the electronic and optical properties of PbS, PbSe and PbTe compounds. The zinc blende (B3), rock salt (B1) and CsCl (B2). crystal structures are considered and the exchange and correlation potential is treated by the generalized-gradient approximation using the Perdew– Burke–Ernzerhof parameterization. Moreover, the modified Becke-Johnson (mBJ) scheme is also applied to optimize the corresponding potential for the band structure calculations. Results show that the rock salt phase is the stable structure in the ground state adopted by PbS, PbTe and PbSe compounds. Moreover, the band structure calculations reveal a semiconductor behavior for all the compounds. The dielectric function, reflectivity, Refractive index and absorption coefficient are calculated to investigate the optical properties.