New UV-enhanced, ultra-low noise silicon avalanche photodiode for radiation detection and medical imaging

New fast, ultra low-noise UV-enhanced avalanche photodiodes (APD) were recently developed by Excelitas Technologies (formerly PerkinElmer Optoelectronics, Vaudreuil, QC, Canada). for use with scintillation crystals. The novel epitaxial type “buried junction” APD structure was designed for detecting photons with wavelengths shorter than ~600 nm at high gain with very low dark current. It typically exhibits extremely low noise level (<;0.1 pA/√Hz per mm²) up to multiplication gains of 200-300. The photodetecting performance of the UV-enhanced APDs with scintillators of potential interest in the fields of high-energy physics and medical imaging is presented. Energy resolution under 8% at 662 keV and subnanosecond timing resolution for annihilation radiation can be reached with LGSO 90% Lu (45 ns).