ABSTRACT
Although scintillator materials are the dominating type of radiation detector in most medical applications, there are systems where other detectors, like semiconductor detectors, may have an advantage. Semiconductor detectors are roughly divided into single-element detectors and compound detectors. While the single-element detectors (Ge and Si) can provide the best energy resolution of all radiation detectors, they have low atomic numbers (z), relatively low densities, and need some form of cooling, making the detector package bulky. On the other hand, compound materials, like CdTe or CdZnTe, can be operated at room temperature and have significantly higher density and Z but worse energy resolution, but still better than all known scintillator materials and may therefore play a role in applications where energy resolution of high-density and Z detectors are of primary concern. This chapter provides a summary of the current status of semiconductor detectors, with a focus on medical applications. Timing properties for TOF-PET applications are discussed for CZT and TlBr materials.
