Gas-source molecular beam epitaxial growth and thermal annealing of GaInNAs/GaAs quantum wells

Abstract

In this paper, we report the growth of GaInNAs/GaAs quantum wells (QWs) by gas-source molecular beam epitaxy with a radio-frequency (RF) nitrogen radical beam source. The influence of growth temperature and N 2 flow rate on GaInNAs/GaAs QWs is examined. At the optimal growth condition, room-temperature photoluminescence (PL) at 1.3 μm is obtained for an as-grown Ga 0.7In 0.3N 0.02As 0.98/GaAs QW. The satellite peaks of the X-ray rocking curves are broader for Ga 0.7In 0.3N 0.03As 0.97/GaAs QWs than for N-free samples, presumably due to composition fluctuations and rougher interfaces, as confirmed by cross-sectional transmission electron microscopy (XTEM) images. Power-dependent PL measurements show that a higher incident laser power causes a larger PL peak blue shift for Ga 0.7In 0.3N 0.03As 0.97/GaAs QWs than Ga 0.7In 0.3As/GaAs QWs. Rapid thermal annealing (RTA) improves interface morphology and PL intensity, reduces the PL peak width, but causes a blue shift in PL peak energy. The optimal annealing temperature is higher for GaInNAs/GaAs QWs than GaInAs/GaAs QWs, indicating the former is thermally more stable. By using RTA, an improved 1.3 μm RT PL emission of a GaInNAs/GaAs QW with stronger intensity and narrower linewidth is obtained successfully.