High efficiency photon detection is a critical component of many nuclear physics detectors- These photon detectors need to exhibit high sensitivity (detect single photons) with wide dynamic range (>1E5 dynamic range), and low noise (< 100 kcps/mm2 at end of life)- Recently, silicon single photon avalanche diode (SPAD) arrays also known as silicon photomultipliers (SiPMs) have been developed to provide a tremendous boost in performance compared to prior solid state solutions (PIN and APDs)- However, silicon has significant shortcomings, including both high beginning of life noise (10 kcps/mm2) and very high end-of-life noise (25 Mcps/mm2 after a 1 MeV neutron equivalent dose of 1E11/cm2)- The proposed SBIR project will develop GaInP based compound semiconductor SPAD arrays to overcome the limitations of silicon based SiPM devices- Ultrasensitive photodetectors are critical components of many nuclear physics detectors- For current and planned upgrades, these photodetectors may encounter significant neutron and charged hadron irradiation, causing a substantial increase in dark count rates and dark current, degrading the noise performance- During the proposed SBIR project, several new generations of GaInP SPAD devices and SPAD arrays will be evaluated for both pre- and post-irradiation performance- Phase II prototype devices will be delivered to end users for evaluation for various proposed detector upgrades-
