Abstract
Electrical and optical measurements of InGaAsP layers grown by liquid-phase epitaxy with different amounts of Er metal (0-0.60 wt %) added to growth solutions are reported. The presence of Er during growth causes the decrease of electron concentration and the strong suppression of donor-related optical transitions due to the effective removal of donors. The characteristic Er 3+ emission lines located in the 1.503-1.542 μm region can only be detected in the 1.3 μm wavelength Er-doped InGaAsP layers. We attribute it to be the formation of a new type of Er 3+ center in the InGaAsP host.