Optical absorption by dilute GaNSb alloys : Influence of N pair states

Abstract

The optical properties of GaNSb alloys with N contents of up to 2.5% have been investigated at room temperature using infrared absorption spectroscopy. The evolution of the absorption onsets with N content has been described using a three level band anticrossing model of the N localized states interactions with the GaSb conduction band. This approach includes the effect of N pair states, which is critical to reproduce the observed optical properties. This confirms theoretical predictions that N pair states have a more pronounced effect on the band dispersion in GaNSb than in GaNAs.