Photoluminescence at 1.54 μm of Er-doped hydrogenated amorphous silicon

Photoluminescence (PL) and light absorption of Er-doped amorphous hydrogenated silicon samples are measured at 77-300 K. The temperature dependence of luminescence of erbium ions in a-Si:H(Er) is compared with that of intrinsic PL of a-Si:H. The lifetime of excited erbium ions in this amorphous matrix changes from 20 to 8 mu s in this temperature range. We propose a defect-related Auger excitation (DRAE) mechanism of erbium luminescence and demonstrate that it is consistent with the whole set of our experimental results. The temperature quenching of the erbium luminescence observed above 200 K, with the activation energy of 250 meV, results from the competition of the DRAE and multiphonon nonradiative defect processes for D-0 + e --> D- transition. (C) 1998 Elsevier Science B.V. All rights reserved.