1.54 μm electroluminescence from erbium doped gallium phosphide diodes

Er-doped GaP diodes that exhibit strong room temperature characteristic 4f-shell luminescence under forward bias have been fabricated. The output of the diode increases linearly with current for low current densities but eventually saturates. The radiative decay lifetime is 2.6 msec and is independent of current. It is proposed that the observed intensity dependence on excitation power results from saturation of the optically active Er³⁺ centers. Some diodes showed a superlinear dependence, with a threshold of about 2 A/cm².