Band gap engineering with sub-monolayer nitrogen insertion into InGaAs/GaAs quantum well

We investigate the band gap engineering with sub-monolayer nitrogen introduction (: N δ-doping) at the middle of InGaAs/GaAs quantum well. Using plasma-assisted molecular beam epitaxy, we prepare samples varying the introduced nitrogen between 0 and 0.4 monolayer. The growths are carried out at substrate temperature of 520∘C, comparatively higher than conventional substrate temperature for dilute nitride compounds. This induces the roughening of the growth front, slightly enhancing the nitrogen incorporation within the crystal. The as-grown and annealed samples show clear room temperature photoluminescence, indicating the band gap shrinkage depending on the amount of nitrogen.