Abstract: An ionizing radiation detector includes a first common semiconductor substrate and a first plurality of single-photon avalanche diode (SPAD) microcell structures disposed at a top face of the first common semiconductor substrate. Each SPAD microcell structure includes a first semiconductor junction that is reverse-biased beyond a first breakdown threshold. The ionizing radiation detector may also include common anode and cathode connections to each of the SPAD microcell structures that operate as an output. The ionizing radiation detector may also include control circuitry connected to the SPAD microcell structures. The control circuitry may be configured to control biasing of the SPAD microcell structures and measure electrical characteristics of a signal provided on the output. Charge drift within the first common semiconductor substrate need not be inhibited from exciting more than one of the SPAD microcell structures of the first plurality of SPAD microcell structures by isolation barriers.

Abstract: An ionizing radiation detector includes a first common semiconductor substrate and a first plurality of single-photon avalanche diode (SPAD) microcell structures disposed at a top face of the first common semiconductor substrate. Each SPAD microcell structure includes a first semiconductor junction that is reverse-biased beyond a first breakdown threshold. The ionizing radiation detector may also include common anode and cathode connections to each of the SPAD microcell structures that operate as an output. The ionizing radiation detector may also include control circuitry connected to the SPAD microcell structures. The control circuitry may be configured to control biasing of the SPAD microcell structures and measure electrical characteristics of a signal provided on the output. Charge drift within the first common semiconductor substrate need not be inhibited from exciting more than one of the SPAD microcell structures of the first plurality of SPAD microcell structures by isolation barriers.