Electrical properties of SnSe under high-pressure

The pressure-induced phase transitions in SnSe have been investigated using the first-principles density functional calculations. The experimental results in the nanostructured SnSe revealed a phase transition at 4 GPa whereas that in the well-crystallized samples showed at 10 GPa. To understand the above discrepancy, we have used a pseudohybrid Hubbard density functional on the fully-relaxed samples of SnSe. The calculated electron energy gap of 0.83 eV is in good agreement with the experimental values of 0.86 eV and 0.898 eV. The analysis of the quasi-particle band structures, Fermi energy level, Fermi-surface indicates a phase transition at 4 GPa in accord with the enthalpy calculations. The Transmission coefficients and the current-voltage characteristics have also been analyzed for 0, 4.0, 7.0 and 10.0 GPa. An increase in the conductivity has been observed with increase in the pressure.