Abstract
The authors report a detailed comparison of low temperature photoluminescence (LTPL) and cathodo luminescence (LTCL) spectra collected in the same stacking faults rich area of a 4H silicon carbide epitaxial layer. In both cases, they find that the maximum wavelength of the defect-related emission lines shifts when the excitation spot position moves across the defect zone. The shift is excitation-intensity dependent. It is very small for LTPL (4 meV) but reach 20 meV for LTCL. This constitutes the first experimental evidence that a screening of the quantum confined Stark effect can be achieved in 4H-SiC SF quantum wells. (c) 2007 American Institute of Physics.