PHOTOLUMINESCENCE AT 1.54 MU-M OF ER-DOPED HYDROGENATED AMORPHOUS-SILICON

Photoluminescence (PL) and light absorption of Er-doped amorphous hydr ogenated silicon samples are measured at 77-300 K. The temperature dep endence 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 r ange. We propose a defect-related Auger excitation (DRAE) mechanism of erbium luminescence and demonstrate that it is consistent with the wh ole set of our experimental results. The temperature quenching of the erbium luminescence observed above 200 K, with the activation energy o f 250 meV, results from the competition of the DRAE and multiphonon no nradiative defect processes for D-0 + e --> D- transition. (C) 1998 El sevier Science B.V. All rights reserved.