A detailed comparison was made of low-temperature photoluminescence and cathodoluminescence spectra collected in the same stacking fault-rich area of a 4H-SiC epitaxial layer. In both cases, it was found that the maximum wavelength of the defect-related emission lines shifted when the excitation spot position moved across the defect zone. The shift was excitation-intensity dependent. It was very small for low-temperature photoluminescence (4meV) but attained 20meV for low-temperature cathodoluminescence. This constituted the first experimental evidence that screening of the quantum confined Stark effect could be achieved in 4H-SiC stacking fault quantum wells.

Screening the Built-In Electric Field in 4H Silicon Carbide Stacking Faults. S.Juillaguet, J.Camassel, M.Albrecht, T.Chassagne: Applied Physics Letters, 2007, 90[11], 111902