Electrical, electronic and optical characterisation of ion beam synthesised beta-FeSi2 light emitting devices

beta -FeSi2/Si light emitting devices (LEDs) have been attracting great int erest since the first successful demonstration of an ion beam synthesised ( IBS) device operating at a wavelength of 1.5 mum. We report here on a study of the electrical, electronic and optical properties of devices produced b y Fe implantation into epitaxial silicon layers. The devices have been char acterised by current-voltage (I-V), capacitance-voltage (C-V), deep level t ransient spectroscopy (DLTS) and electroluminescence (EL) measurements. DLT S showed the presence of a majority carrier trapping centre, with an activa tion energy of 200 +/- 25 meV. Room temperature EL was observed from beta - FeSi2/Si LEDs, Preliminary analysis of the EL results suggests its quench r atio depends on device structure; the quenching is thought to be related to surface recombination. (C) 2001 Elsevier Science B.V. All rights reserved.