Theoretical Study of Energy Band Gap for Chalcogenides Under High Pressure

In the present study, we have calculated the energy band gap of some chalcogenides viz. Na₂S and Na₂Se, using the equation from Angilella et al. (JPCS 121:032006, 2008) to analyze the variation of energy band gap under high pressure with respect to the lattice constant. To determine the pressure, we using some different equation of state viz. Murnaghan EOS, Hama-Suito EOS, Vinet-Rydburg EOS, Birch-Murnaghan EOS and Shanker EOS. The energy band gap of chalcogenide materials similarly behaves like other semiconductors when influenced by high pressure. The result of our calculations for the lattice constant under high pressure indicate that the lattice constant decreases as pressure increases. Furthermore for, Na₂S and Na₂Se materials at high pressure, our results show that the energy band gap increases as pressure increases for all EOSs.