Performance of ultra-small silicon photomultiplier array with active area of 0.12 mm×0.12 mm

Abstract

We report the performance of an ultra-small silicon photomultiplier (SiPM) line array with 7 elements of 0.12×0.12mm2 in active area, 0.2mm in pitch and 120 micro cells in one element. The device features an epitaxial bulk quenching resistor concept, demonstrated high geometrical fill factor of 41% and photon detection efficiency (PDE) of 25.4% in the wavelength region between 430nm and 480nm while retaining high micro cell density around 10000mm−2 and ~3ns FWHM of dark pulses width; it also demonstrated dark count rate of less than 28.7kHz, optical crosstalk of the order of 2% to 4%, and excellent photon number discrimination. A 0.15mm×1.6mm×1.6mm lutetium yttrium oxyorthosilicate (LYSO) crystal, corresponding to the width, length and height respectively, was successfully coupled to the 1×7 SiPM array for possible ultra-highly resolved positron emission tomography (PET) applications. This novel type of device has advantages particularly for small active area since the performances, such as PDE and response speed is one of the best among SiPMs with similarly high density of micro cells. It may pave a way for this type of SiPM as a promising pixel position sensitive device in imaging sensor applications.