1.54 μm luminescence quenching of erbium-doped hydrogeated amorphous silicon deposited by DC magnetron sputtering

Erbium was doped onto hydrogenated amorphous silicon using the D.C. magnetron sputtering technique. After annealing under oxygen atmosphere at 350 degreesC, a-Si: H<Er> films with variable optical gaps exhibits efficient room temperature at 1.538 mum. The intensities of the 1538 and 1549.6 nm Er(3+) lines at room temperature were 15 and 12%, respectively, of those at 15K. This result suggests that DC sputtered a-Si:H is a suitable host for efficient Er(3+) emission at room temperature. Amorphous silicon has an erbium solubility higher than 10(20) cm(-3) and a greatly reduced thermal quenching of the erbium PL due to a less efficient excitation energy transfer. The observation of efficient room temperature luminescence from erbium-doped a-Si:H films involves impurities such as oxygen. We found that the increase in the optical cap and the electrical resistivity of the a-Si: H<Er> films produced at low substrate temperature (high defect density, low gap) is more important than that in material deposited at 240 degreesC. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.