Molecular beam epitaxy of self-assembled GaSb-based quantum dot structures for the control of photoluminescence wavelengths towards 1.3 μm range

Self-assembled GaSb quantum dots were fabricated on [001] GaAs by molecular beam epitaxy using Sb₄ as V group element. GaSb dots showed anisotropic shape elongating along <110> orientation. The Sb₄ beam fluxes during growth of GaSb affect the dot´s elongation ratio and the densities. The quantum dot PL emission energy showed a blueshift when the GaSb dots were covered a GaAs cap layer grown at 580°C compared with that grown at 500°C. By varying the GaSb coverage, the PL peaks from quantum dots can be controlled to reach emission wavelength on optical communication range.