A new empirical interatomic potential for compound semiconductors and its application to thermodynamic stabilities

We proposed a new empirical interatomic potential for compound semiconductors applicable to estimation of subtle energy difference. The potential was devised to incorporate the interactions between atoms beyond 3rd neighbors by considering electrostatic contributions. The versatility of the potential was confirmed by the calculation of relative stabilities between wurtzite and zinc blende structures. Using the new potential, we also worked out the excess energies for In_xGa_1-xN/GaN and In_xGa_1-xN/InN in order to investigate thermodynamic stabilities. We found that the excess energy maximum drastically shifted toward x∼0.80 for InGaN/GaN and x∼0.10 for InGaN/InN due to the lattice constraint from the bottom layer in contrast with x∼0.50 for bulk.