Temperature dependence of photoluminescence spectra from multiple Er³⁺ sites in Er-implanted undoped and Mg-doped GaN

Selectively excited photoluminescence (PL) spectroscopy has been carried out on the ∼ 1540 nm ⁴I_13/2 to ⁴I_15/2 emissions of the multiple Er³⁺ centers observed in Er-implanted undoped and Mg-doped GaN at temperatures ranging from 6 to 295 K. The temperature dependence of the Er³⁺ PL spectra selectively excited by below-gap light demonstrate different quenching rates for the distinct Er³⁺ PL centers, and indicate that the PL spectra with the most rapid thermal quenching rates do not contribute to the room temperature, above-gap-pumped Er³⁺ PL spectrum. In addition, selective PL spectroscopy has been carried out on the Er³⁺ emission in Er-implanted undoped and Mg-doped GaN at temperatures ranging from 6 to 295 K. The results indicate that the previously reported enhancement of the violet-pumped centers' contribution to the low temperature above-gap excited Er³⁺ PL in Mg-doped GaN is also evident at room temperature.