Effects of ( NH 4 ) 2 S and NH 4 OH surface treatments prior to SiO 2 capping and thermal annealing on 1.3   μ m GaInAsN/GaAs quantum well structures

We report the influence of ( NH 4 ) 2 S and NH 4 OH surface treatments prior to SiO 2 capping and subsequent rapid thermal annealing, on optical properties of GaInAsN/GaAs quantum-well (QW) structures. We observed an increase in QW photoluminescence (PL) emission for the ( NH 4 ) 2 S treated samples as compared to the untreated sample. After annealing, also the NH 4 OH treated sample showed significant improvement in PL. The treatments were also found to decrease the In out-diffusion and reduce the blueshift upon annealing. The PL results are discussed with x-ray diffraction and x-ray photoemission data from SiO 2 / GaAs , in particular, with changes found in Ga 3 d spectra.