We present a photoluminescence (PL) study of Er-doped AlN epilayer on sapphire substrate. The AlN : Er film was grown by metalorganic molecular beam epitaxy and an Er concentration of 2–5 × 1019Er/cm3 was obtained. Following the excitation of an argon ion laser at 488 nm, we observed a strong 1.54 μm Er3+ luminescence, which is quenched by only a factor of two between 15 K and room temperature. The photoluminescence excitation (PLE) spectrum, as well as PL lifetime measurement suggest that at 488 nm, Er3+ is excited through a photo-carrier mediated process. In contrast, exciting AlN : Er at ~525 nm seems to result in the direct excitation of an intra-4f transition of Er3+.
