A study of the mechanisms responsible for blue emission from arsenic-dopedgallium nitride

We have investigated the influence of the growth conditions on the intensit y of blue emission at room temperature from As-doped GaN samples grown by m olecular beam epitaxy. A series of As-doped GaN samples was grown at 800 de greesC with constant fluxes of As and gallium, but with different amounts o f active nitrogen. Varying the N flux allowed us to investigate films grown from strongly Ga-rich conditions to more N-rich conditions. The blue emiss ion increases monotonically with the nitrogen flux and is most intense in t he layers grown under the most nitrogen-rich conditions. This fact suggests that As atoms incorporated into the Ca sub-lattice are responsible for the strong blue emission in As-doped GaN.