Photoluminescence of undoped and Er-doped 1.1-μm InGaAsP layers grown by liquid-phase epitaxy

Abstract

1.1-μm InGaAsP epitaxial layers lattice-matched to InP substrates have been grown by liquid-phase epitaxy. From photoluminescence (PL) measurements at various temperatures and excitation levels from the undoped InGaAsP layers, the three peaks observed are associated with the near-band-to-band, shallow- and deep-donor-to-acceptor pair transitions. This is the first report to identify the PL spectrum of the 1.1-μm InGaAsP layers. The shallow and deep donors present in the undoped layers can be effectively reduced using erbium as a gettering source. With increasing Er amount in the InGaAsP growth solution, the electron concentrations in the Er-doped layers are one to two orders of magnitude lower than those of undoped layers. As the Er amount is increased above 0.54 wt%, the near-band-to-band peak dominates the PL spectrum and exhibits a full width at half maximum of 9.3 meV.