Pixel detectors are an integral part of medical imaging, particle physics, and many other research areas. Sensors are made from various types of materials such as GaAs, Si, CdTe. Current research tends to use CdTe as X-ray sensors due to its high absorption coefficient in the X-ray spectrum. With decreasing size of pixels, charge diffusion causes charge sharing between neighboring pixels. That decreases the spatial and spectral resolution.
This study simulated the effects of charge diffusion in a 2 mm thick 70 µm pixelated CdTe. We created a sensor model with an array of 5 x 5 pixels, and we simulated the propagation of e-h pairs generated upon absorption of a gamma photon. Based on the simulation outcome, we calculated the total charge distribution between neighboring pixels, and we estimated the dynamic range in electrons of the analog front-end amplifier. Finally, we created a Verilog-A sensor model, which is to be used for analog front-end design.
|Funding information||This work was supported by Centre of Advanced Applied Sciences CZ.02.1.01/0.0/0.0/16-019/0000778, co-financed by the European Union.|
|TIPP2020 abstract resubmission?||No, this is an entirely new submission.|