The properties of a Pd-Au complex in n-type Si are investigated by DLTFS (deep level transient Fourier spectroscopy) techniques. In n-type Si the energy level of the Pd-Au complex is slightly shifted with isochronal annealing and does not display stable properties. The defect reaction of Pd-Au is explained by an ''enhanced kick-out'' mechanism represented by the reaction equation Au-i + Pd-s --> Au-s + Pd-i, where interstitially diffusing gold replaces substitutional palladium. This reaction is similar to the Au-Rh defect reaction. The results of the investigations of the properties of the Pd-Au complex in p-type Si will be published later.

Metalorganic vapour-phase epitaxy (MOVPE) growth experiments for GaAs and (AlGa)As have been performed as a function of growth temperature and VIII ratio using the new alternative precursor diethyl-tert-butylarsin (DEtBAs) in combination with trimethylgallium (TMGa) and trimethylaluminium (TMAl). The incorporation of deep traps has been investigated by means of photoluminescence (PL) and deep level transient Fourier spectroscopy (DLTFS). In (AlGa)As layers grown with DEtBAs a drastic reduction of the deep broad band luminescence between 1.5 and 2 eV is observed in dependence of the growth conditions. A probably deep complex defect involving an As vacancy is observed in (AlGa)As layers grown with DEtBAs. In GaAs layers grown with DEtBAs or AsH3 the dominant deep trap is the EL2 defect. Deep level photoluminescence studies show a reduced incorporation of the EL2 defect as compared to AsH3 grown layers, due to the smaller VIII ratio. The obtained low deep defect concentration in particular for GaAs layers underlines the great potential of the model precursor DEtBAs as substitute for the highly toxic AsH3 in MOVPE.