Structural and optical properties of GaAlInAs lattice matched to InP grown by low-pressure metalorganic vapor phase epitaxy

We report for the first time, the metalorganic vapor phase epitaxy (MOVPE) growth of the quaternary alloy GaxAlyIn1−x−yAs, lattice matched to InP. Single epitaxial layers were prepared showing specular morphologies and lattice matching within Δa/a=10−3. Epilayers showed a high degree of crystallinity with routine x-ray linewidths of 20–40 seconds of arc. The lowest linewidth achieved was 22 seconds of arc. Room temperature and 4 K photoluminescence (PL) studies demonstrated very narrow excitonic transitions with ΔE at 4 K down to 5.4 meV. Band-gap energies, obtained from the absorption edge and PL peak energies, plotted against Al composition showed that the alloy was best described by a straight line relationship between the ternary end points, Ga0.47In0.53As and Al0.48In0.52As with no bowing observed.