Cathodoluminescence dependence on beam generation conditions and surface properties of materials

The Cathodoluminescence (CL) dependence on the beam generation conditions and the surface properties of the sample has been investigated in various semiconducting materials including, CdS, GaAs and ZnO. CL measurements have been performed on chemically polished, mechanically polished and cleaved surfaces. The results show a strong effect of the surface preparation on the defect band of the sintered CdS polycrystals. The variation of the CL intensity and the peak energy upon the primary beam energy and current has been compared for both edge and defect luminescence of different materials. The results show a linear increase of the CL edge emission versus the beam current in all materials while the defect emission in CdS presents a sublinear dependence. Furthermore, the defect luminescence increases linearly with the acceleration voltage while the edge luminescence in CdS shows a maximum.