Papers by Author: Jorge Andres Guerra

Abstract: Amorphous pseudobinary (SiC)1 x(AlN)x thin films have been produced by radio frequency dual magnetron sputtering from bulk SiC and AlN targets. For each target the emission characteristic, i.e. the spatial variation of the deposition rate was determined, in order to predict thickness distribution and spatial composition variation for the (SiC) (AlN) alloy. Impedance spectroscopy shows a high resistivity of the films in the SiC rich region, decreasing significantly towards the AlN rich region.

Abstract: Amorphous wide bandgap semiconductor thin films of the pseudobinary compound (SiC)1-x(AlN)x were grown by radio frequency dual magnetron sputtering on CaF2, MgO and glass substrates. We performed isochronical annealing steps up to 500°C. The optical bandgap is determined for each composition from spectroscopic transmission measurement in two different ways: according to Tauc and using the (αhν)2 plot. The dependence of the optical bandgap on the composition x can be described by Vegard’s empirical law for alloys.

Abstract: We produce amorphous terbium doped wide bandgap semiconductor thin films of the pseudobinary compound (SiC)1 x(AlN)x by rf triple magnetron sputtering. Cathodoluminescence measurements performed at samples having different compositions x show pronounced intra 4f shell transition peaks of the trivalent terbium. Thermal activation of the terbium emission by isochronal annealing of the films leads to a strong increase in emission intensity.