Photoluminescence optimization and characteristics of the rare-earth element erbium implanted in GaAs, InP, and GaP

The characteristic 1.54-μm emission from the rare-earth element erbium implanted in GaAs, InP, and GaP was investigated through 10-K photoluminescence essentially as a function of anneal temperature, time, and method. The strip-heater, forming-gas, and quartz-ampoule anneal methods were utilized in the range of 400 to 1000 °C. Erbium-related emissions were observed from 1.48 to 1.64 μm and were observable at emission temperatures of up to 260 K for InP:Er and 296 K for GaP:Er and GaAs:Er. Out of the three semiconductors, GaAs:Er was observed to exhibit the highest optical activation using a square-profile implantation technique. Dependent on the anneal method, optimum Er emissions occurred between 650 and 800 °C for GaAs, for InP between 575 and 625 °C, and for GaP between 800 and 950 °C. In general, the forming-gas anneal method proved most successful; however, maximum luminescence including sharper emission lines was achieved through the strip-heater method. This method, with an anneal time of 10 s, showed also the importance of short-time anneals in GaAs:Er, results which were also paralleled by isothermal anneals of InP:Er. The difference in emissions at different anneal temperatures and times gives preliminary evidence of different Er3+ centers.