1.54 &mgr;m photoluminescence has been observed from GaN doped with Er during growth by metalorganic molecular beam epitaxy. StrongEr3+-related photoluminescence (PL) was measured at room temperature for GaN:Er doped during growth onc-planeAl2O3and 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 of3×1018 cm−3with[O]∼1020 cm−3and[C]∼1021 cm−3luminesce at 1.54 &mgr;m with an intensity ∼2 orders of magnitude greater than films with oxygen and carbon backgrounds of less than1019 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&percent; between 15 and 300 K while the integrated PL signal from the samples with lower [O] and [C] quenched ∼85&percent; over the same temperature range. ©1998 American Institute of Physics.