Photoluminescence study of type-Il InGaPN/GaAs quantum wells

Nearly lattice-matched ln _0.528Ga _0.472P _1-yN _y bulk layer and ln _0.528Ga _0.472P _1-yN _y/GaAs and GaAs! ln _0.528Ga _0.472P _1-yN _y quantum wells with higher N content, y = 0.O ₂7, were grown on GaAs(001) substrates by metalorganic vapor phase epitaxy. High-resolution X-ray diffraction results demonstrated the high quality of both the layer and quantum wells with fairly flat interfaces. Temperature dependent photoluminescence results showed that a near-band-edge emission is dominant in the bulk ln _0.528Ga _0.472P _1-yN _y layer, which at low temperature (T < 100 K) is associated with localized emissions centered at ̃1 .73 eV. Bandgap of ln _0.528Ga _0.472P _1-yN _y was examined to be 1.81 and 1.78 eV at 10 K and room-temperature, respectively. Low temperature (10 K)photoluminescence spectrum obtained from the GaAs!ln _0.528Ga _0.472P _1-yN _y quantum well also exhibited red emission at 1.73 eV attributed to the emission from the InGaPN barrier. In addition, there are the extra weak peaks appear in a near-infrared energy range at 1.357 and 1.351 eV for ln _xGa _1-xP _1-yN _yGaAs and GaAs/ln _xGa _1-xP _1-yN _y quantum wells, respectively. Such optical transitions are considered as an indirect transition between electrons located in the InGaPN and holes located in the GaAs regions. This situation suggested that both the In _0.528Ga _0.472P _0.973N _0.O27/GaAs and GaAs/In _0.528Ga _0.472P _0.973N _0.O27 quantum wells exhibits a type-Il quantum structure. This interpretation is justified when the valence and conduction band offsets of the type-Il band alignment, which are relatively approximated to be 450 and 160 meV, are properly taken into account.