Introduction to Detector Technologies

Most modern-day pixelated semiconductor X-ray detectors are realized as monolithic or hybrid pixel detectors, where the primary difference between the two is whether the sensor is part of the same piece of semiconductor as the readout electronics. In the case of a monolithic detector, the sensor and the electronics are incorporated into the same semiconductor piece. While this can offer advantages with respect to noise and reduce interconnection complexity, it limits the sensor material to Silicon (Si). However, for hybrid pixel detectors, the sensor and the electronics are made from separate semiconductor dies and bonded using various interconnect technologies. As such, this type of detector will have lower noise performance but allow for flexibility in the semiconductor material used as a sensor. This preparatory chapter provides a top-level description of the basic physical principles guiding the operation of these types of detectors and an introductory explanation of various electronic readout schemes implemented to process the X-ray-generated charge pulse.