Simulation of charge transport in pixelated CdTe

Area of Science:

• Nuclear Medicine
• Semiconductor Technology
• Medical Imaging

Background:

• Pixelated semiconductor detectors offer potential for improved nuclear medicine imaging.
• Current limitations in detector technology can impact image reconstruction efficiency and resolution.
• The Voxel Imaging PET (VIP) Pathfinder project aims to leverage these advancements.

Purpose of the Study:

• To demonstrate the advantages of pixelated semiconductor technology for nuclear medicine applications.
• To design advanced detectors for Positron Emission Tomography (PET), Positron Emission Mammography (PEM), and Compton gamma cameras.
• To achieve improved image reconstruction without efficiency loss.

Main Methods:

• Utilizing pixelated Cadmium Telluride (CdTe) Schottky detectors with 1x1x2 mm³ voxels.
• Employing a dedicated application-specific integrated circuit (ASIC) for each readout channel.
• Simulating charge carrier behavior in CdTe using Finite Element Method (FEM) Multiphysics COMSOL software.
• Combining COMSOL simulations with GAMOS Monte Carlo software for comprehensive charge sharing evaluation.

Main Results:

• Detailed understanding of signal charge carrier behavior in CdTe.
• Extraction of charge sharing values based on impact point and bias voltage using COMSOL.
• Full evaluation of charge sharing in pixelated CdTe for various gamma impact points through integrated simulations.

Conclusions:

• Pixelated CdTe Schottky detectors with dedicated ASICs show promise for high-resolution nuclear medicine imaging.
• Accurate simulation of charge carrier behavior is crucial for optimizing detector performance.
• The VIP Pathfinder project's approach enables improved image reconstruction in PET and other nuclear imaging modalities.