Recent research progress of silicon photomultiplier with epitaxial quenching resistor

The Novel Device Laboratory (NDL) of Beijing Normal University has been developing a silicon photomultiplier with an epitaxial quenching resistor (EQR SiPM), which has a compact structure and a relatively simple fabrication process. Recently, to meet the requirements of nuclear medicine imaging, NDL has successfully developed an EQR SiPM with a microcell size of 15 μm and an active area of 9 mm² by optimizing the device structure and fabrication technology. Compared to previous devices of the same type, the dark count rate (DCR) of the EQR SiPM is further reduced while still maintaining high photon detection efficiency (PDE). At an ambient temperature of 20 ℃ and an operating overvoltage of 7 V, the typical DCR is 226 kHz/mm², and the peak PDE is 46%. In addition, to further increase the dynamic range of the EQR SiPM, NDL has developed an EQR SiPM with a microcell size of 6 μm, an active area of 9 mm² and a microcell number of 244720. At an ambient temperature of 20 ℃ and an operating overvoltage of 7 V, the typical DCR is 240 kHz/mm², and the peak PDE is 28%. It has large dynamic range that is very suitable for the measurement of high-energy cosmic rays and other applications in hadron calorimeters.