Density functional theory study : Electronic structures of RE:GaN in wurtzite Gα15RE1N16

Abstract

Gallium nitride (GaN) is a wide-band gap (Eg=3.4eV) semiconductor. Rare-earth (RE) in GaN have attracted interest due to their potential applications. Electronic structure calculations were performed for substitutional rare-earth (Pr, Er, Eu, Nd, and Dy) in wurtzite supercell GaN using density functional theory calculations within the GGA approach. Our calculations show that RE doped in GaN exhibit an indirect band gap and introduces an impurity level. We found the equilibrium bond lengths of RE-N are vary between 2.13 to 2.253Å in good agreement with structural data available for Eu and Er. We confirm that the present supercell model well describes the state of RE in GaN. Its predicts the band gap narrowing that expected to improve the optical performance of GaN.