The influence of edge effects on the detection properties of cadmium telluride

Driven by the demand of various applications for a detection area that is larger than the active area of a single detector module, we explore the possibility to realise a large-area detector by a seamless tessellation of multiple detectors. This requires sensors with a minimum amount of dead area at the edge. In order to be able to reduce this area, edge effects must be understood and avoided or mitigated. In this paper, we report on first tests that are performed on diamond-blade diced slim-edge pieces of cadmium telluride with a last-pixel-to-edge distance of only 65 µm. The results indicate that the edge-pixel response is not significantly affected with respect to the leakage current and the charge collection efficiency. First measurements towards a quantification of the detective quantum efficiency have been made on edge pixels by determining the pixel response function and the noise power spectrum.