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Bandgap engineering of the amorphous wide bandgap semiconductor (SiC)1−x(AlN)x doped with terbium and its optical emission properties

2010; Elsevier BV; Volume: 174; Issue: 1-3 Linguagem: Inglês

10.1016/j.mseb.2010.03.033

1873-4944

Roland Weingärtner, J. A. Guerra, Oliver Erlenbach, G. Gálvez de la Puente, F. De Zela, A. Winnacker,

Silicon Nanostructures and Photoluminescence

Amorphous wide bandgap semiconductor thin films of the pseudobinary compound (SiC)1−x(AlN)x doped with terbium were grown by trial rf magnetron sputtering on CaF2 and glass substrates. The optical bandgap of the films in dependence of the composition x has been determined from transmission measurements using the (αhν)2 versus energy plot and the Tauc-plot. The bandgap varies from 2.2 eV for x = 0 (SiC) to 4.7 eV for x = 0.94 (almost pure AlN) and can be described by Vegard's law using the bowing parameter (3.18 ± 1.01) eV. Cathodoluminescence measurements show the typical terbium emission pattern. Thermal activation of the thin films with isochronical annealing from 300 °C to 1150 °C leads to strong increase of the emission with an optimal annealing temperature of 1100 °C.