Readout cross-talk for alpha-particle measurements in a pixelated sensor system

Abstract

Simulations in Medici are performed to quantify crosstalk and charge sharing in a hybrid pixelated silicon detector. Crosstalk and charge sharing degrades the spatial and spectral resolution of single photon processing X-ray imaging systems. For typical medical X-ray imaging applications, the process is dominated by charge sharing between the pixels in the sensor. For heavier particles each impact generates a large amount of charge and the simulation seems to over predict the charge collection efficiency. This indicates that some type of non modelled degradation of the charge transport efficiency exists, like the plasma effect where the plasma might shield the generated charges from the electric field and hence distorts the charge transport process. Based on the simulations it can be reasoned that saturation of the amplifiers in the Timepix system might generate crosstalk that increases the charge spread measured from ion impact on the sensor.

Heteroepitaxial passivation of Cs2AgBiBr6 wafers with suppressed ionic migration for X-ray imaging

“…Previous Pb-based perovskites typically exhibit severe ionic migrations, excluding the use of large bias. We want to emphasize that high bias voltage is highly important for radiation detections, as it reduces the carrier transit time between electrodes, decreases the carrier diffusion length perpendicular to the electric field direction, and thereby prohibits the signal crosstalk between different pixels for imaging applications 31 . The imaging contrast result was shown in Fig.…”

Ultralow Detection Limit and Robust Hard X-ray Imaging Detector Based on Inch-Sized Lead-Free Perovskite Cs3Bi2Br9 Single Crystals

“…As a high bias voltage reduces the carrier mobility time between electrodes, the carrier diffusion length decreases, which prohibits the signal crosstalk between different pixels for X-ray imaging applications. 11 Moreover, perovskite crystalbased X-ray imaging systems can attain a higher resolution and realize faster and easier imaging using smaller detector pixels integrated in the readout circuity. 55 Therefore, the stable highresolution hard X-ray imaging of the present X-ray detector could be attributed to the ultralow dark current drift, ultralow detection limit, high sensitivity, and suppressed ion migration of the CBB SC.…”

“…Several researchers reported on hard X-ray detection with photon energies larger than 80 keV, which are suitable for computed tomography (CT) imaging and inspection systems necessitating strong penetration in the objects. 10,11 Notably, MAPbBr 3 (MAPB) SCs yielded a sensitivity of 3928.3 μC Gy air −1 cm −2 for 120 keV hard X-ray detection. 11,12 To efficiently stop hard X-ray photons, SCs with millimeter thickness are desired owing to their low trap density, free grain boundary, and high stability.…”

“…10,11 Notably, MAPbBr 3 (MAPB) SCs yielded a sensitivity of 3928.3 μC Gy air −1 cm −2 for 120 keV hard X-ray detection. 11,12 To efficiently stop hard X-ray photons, SCs with millimeter thickness are desired owing to their low trap density, free grain boundary, and high stability. 13,14 Moreover, a high electric field can facilitate the collection of photon-generated charges at the metal electrodes deposited on both sides of the crystal.…”

“…However, most of the existing studies on perovskite films focused on the detection of X-rays with a photon energy of less than 70 keV, the application of which is limited to scientific research and medical diagnosis fields, such as X-ray diffraction (XRD), X-ray fluorescence, mammography, and chest radiography, owing to the limited penetration depth. Several researchers reported on hard X-ray detection with photon energies larger than 80 keV, which are suitable for computed tomography (CT) imaging and inspection systems necessitating strong penetration in the objects. , Notably, MAPbBr 3 (MAPB) SCs yielded a sensitivity of 3928.3 μC Gy air –1 cm –2 for 120 keV hard X-ray detection. , To efficiently stop hard X-ray photons, SCs with millimeter thickness are desired owing to their low trap density, free grain boundary, and high stability. , Moreover, a high electric field can facilitate the collection of photon-generated charges at the metal electrodes deposited on both sides of the crystal. However, a high bias can significantly increase the dark current noise and current drift caused by the relatively low resistivity and strong ionic migration in most three-dimensional (3D) perovskites, respectively, which can deteriorate the resolution and stability of the detector. , …”