Effects of using As_2 and As_4 on the optical properties of InGaAs quantum rods grown by molecular beam epitaxy

摘要

We investigate the effect of the arsenic source (AS_2 and AS_4) on the optical properties of InGaAs quantum rods (QRs) grown by molecular beam epitaxy. Owing to differences in the In and Ga diffusion lengths under AS_2 and As_4 fluxes, photoluminescence (PL) peak energies of the QR samples depend strongly on the As source when similar growth conditions are used. A marked improvement in the PL intensities from QR samples grown using As_4 is achieved. However, for both AS_2 and As_4, an increase of the As overpressure results in a PL intensity degradation, probably due to the formation of nonradiative recombination centers.