Photoluminescence in SiCGe thin films grown on 6H-SiC

Intense visible luminescence is observed at room temperature from SiCGe films on 6H-SiC (0 0 0 1) substrate. The PL intensity increases rapidly under the UV laser excitation during the first 2 h. This phenomenon may be explained by an effect similar to the Steabler-Wronski effect in hydrogenated amorphous Silicon. High density of defects such as double phase boundaries and stacking faults are observed by TEM characterization, which produce the quasidefects and accelerate the effect.