Study on nitrogen-induced defects formation and annealing effects in TlInGaAsN alloysystem

► TlInGaAsN samples were grown by gas-source molecular-beam epitaxy on GaAs (001) substrate. ► The change of N-related defects in TlInGaAsN after annealing was investigated by X-ray photoelectron spectroscopy (XPS). ► Annealing treatment reduces the defect concentration and induces a significant improvement in the PL efficiency.