Structural and photoluminescence analysis of Er implanted LT-GaAs

Characteristic 1.54 μm Er³⁺ emission has been observed from Er-implanted and annealed, low-temperature grown GaAs (Be doped and undoped samples). Cross-sectional transmission electron microscopy (TEM) studies reveal very little structural damage for elevated temperature implants up to an Er total fluence of 1.36×10 ¹⁴ Er/cm². No Er emission was observed from any of the as-implanted samples. Post-implantation annealing optimized the Er PL emission intensity near 650°C for Be doped samples, while for undoped samples it was near 750°C anneal. The beginning of Er precipitation was observed after 750°C annealing for the above Er fluence but, on increasing the Er concentration by higher implantation fluences, it was observed after annealing at 650°C. These precipitates are likely ErAs