Annealing effects of diluted GaAs nitride and bismide on photoluminescence

摘要

Effects of the post-growth thermal anneal on the optical properties of GaNAsBi were systematically investigated. By the addition of Bi into diluted GaAs nitride alloy to form quaternary GaNAsBi alloy, the optical property of the diluted GaAs nitride alloy is improved which is confirmed by the photoluminescence (PL) emission from as-grown GaNAsBi samples at room temperature. The PL intensity of GaNAsBi is remarkably improved by post-growth thermal annealing process. By comparing the results of PL intensities of GaAs_(0.978)Bi_(0.022), GaN_(0.01)As_(0.99), and GaN_(0.01)As_(0.968) Bi_(0.022), the improvement in PL intensity of GaN_(0.01)As_(0.968)Bi_(0.022) by anneal can be attributed to an inherited nature of GaNAs. Incorporation of Bi may suppress the blue shift induced by N incorporation. Based on results of X-ray diffraction, the blue shift is probably caused by a microscale reorganization of N and Bi mainly inside the epilayers with keeping the average N and Bi concentrations constant.