Er doping of GaN during growth by metalorganic molecular beam epitaxy

Abstract

1.54 μm photoluminescence has been observed from GaN doped with Er during growth by metalorganic molecular beam epitaxy. Strong Er3+-related photoluminescence (PL) was measured at room temperature for GaN:Er doped during growth on c-plane Al2O3 and Si. Experiments to evaluate the effects C and O on the optical activity of Er indicated that these impurities dramatically enhance Er PL in GaN. GaN films doped with Er to a concentration of 3×1018 cm−3 with [O]∼1020 cm−3 and [C]∼1021 cm−3 luminesce at 1.54 μm with an intensity ∼2 orders of magnitude greater than films with oxygen and carbon backgrounds of less than 1019 cm−3. The thermal PL quenching behavior was also markedly different for samples of varying O and C content. Er3+ luminescence from samples with high O and C concentrations quenched by only 10% between 15 and 300 K while the integrated PL signal from the samples with lower [O] and [C] quenched ∼85% over the same temperature range.