Large Area, Low Dark Count VIS-UV Solid State Photomultipliers

The need for domestic sources of improved-performance single photon counting detectors (SPDs) is important for the advancement of science. SPDs are proving invaluable for studying intracellular processes, charged particle physics, adaptive optics for extremely large telescopes, and numerous other applications. However, existing SPDs have many deficiencies that prohibit their widespread application. Since silicon is by far the best understood and the most frequently used semiconductor material, it is not surprising that nearly all manufactured types of large area SPDs are based on silicon. While technologies such as silicon photomultiplers (SiPMs) are gaining acceptance for some applications, for others, the high dark count rate, low sensitivity, and high cost prohibit their use. Needed for such photon applications are new SPD technologies. Many of the applications for SiPM detectors are for wavelengths below the silicon bandgap. It is proposed that using materials with a wider bandgap, which exploit the economies of scale that are available in GaAs wafer and processing technologies offers a superior solution for large, high count rate compound semiconductor alternatives to SiPM detectors. A solid state photomultiplier (SSPM) is proposed based on the AlGaAs material system. A series of AlGaAs Geiger mode (Gm) pixel elements will be designed and demonstrated, alone, and configured in parallel. The superior photon detection efficiency, count rate, and dark count rate performance of the AlGaAs SSPM detector will be demonstrated. It will also be shown that the AlGaAs SSPMs can be made at a lower cost than comparable performance SiPM technology. Commercial Applications and Other Benefits: The need for domestic sources of improved-performance SSPM detectors is important for the advancement of science, as SSPM are proving to be invaluable for measuring the output of scintillating fibers, tiles, and high-Z scintillators. The need for domestic sources of improved-performance detector detector arrays is also important for medical applications, such as PET, and for measuring the intracellular process, as well as other applications.