Photoluminescence properties of dilute nitride InNAs/InGaAs/InP multi-quantum wells for mid-infrared applications

We report the photoluminescence characterization of a series InNAs/InGaAs multi-quantum wells (MQWs) of various N content on InP substrates. The emission wavelength of these QWs can be tuned effectively by N content. However, the bowing effect is weaker than in GaNAs and GaInNAs. The optical properties of these hetero-structures are closely related to quality of the interface between the barriers and the QWs which is influenced by N content. Two effects of N in this material system have been clarified. On the one hand, the incorporation of N into InAs matrix is beneficial as far as the reduction of band-gap and the lattice constant are concerned. On the other hand, the PL efficiency increases dramatically with the increase of N content. Optimized design and growth could be achieved by trading off between these two effects.