The Ga-based Solid State Photomultipliers

The design of future calorimeters used in nuclear physics experiments are limited by existing photodetector technologies, the photomultiplier tube and the silicon photomultiplier- The former requires high voltage, is not compact, and is sensitive to magnetic fields, where the latter is not radiation hard and is limited in area due to dark noise- The fundamental silicon photomultiplier design is to be transferred to a non-silicon semiconductor that is more radiation tolerant and has a bandgap energy larger than silicon- The family of Ga-based semiconductors has been researched for this application, yet the ideal material or fabrication process has not been defined- From performance limitations seen in AlGaAs and GaAs Geiger photodiodes (GPD), the overall objective of the Phase-1 effort is to demonstrate the feasibility by identifying a candidate Ga-based material, identifying the noise sources, and proposing a fabrication method to minimize the noise terms-