N2-incorporation-induced blue shift in InGaAsN/GaAs quantum well during annealing

Three different kinds of quantum wells (QWs) were grown at the same growth temperature by molecular beam epitaxy (MBE): InGaAs/GaAs QW without any N2 background; InGaAs(N2)/GaAs double QWs with N2 flow to the sample but without plasma; and InGaAsN/GaAs QW with N-plasma. The latter two types of QW were grown on one sample. Post-growth rapid thermal annealing (RTA) was applied to them at 700 °C. After 31.5 min of RTA, it was observed that the photoluminescence blue shift of the InGaAs(N2) QW was 40 meV, which was 9 meV more than that for the InGaAsN QW, and the InGaAs QW had only about 13 meV blue shift. However, for the as-grown case, the PL peak position of the InGaAs QW and InGaAs(N2) QWs were the same (1148 nm), and for the InGaAsN QW it was 220 nm longer. This indicates that there is N2 incorporation during InGaAsN growth, the N2 incorporation does not affect the band structure and the N2 incorporation dominates the blue shift during RTA.