外延电阻淬灭型硅光电倍增器(EQR SiPM)的特点是利用硅衬底外延层来制作器件淬灭电阻。为了进一步提高大动态范围EQR SiPM的光子探测效率, 并且解决填充因子较低和增益较小等问题, 在前期研究工作的基础上研制出微单元尺寸分别为15 μm和7 μm的EQR SiPM, 有源区面积均是1 mm×1 mm。通过改变EQR SiPM的微单元尺寸优化填充因子, 有效提高了探测效率与增益; 其微单元密度分别是4 400个/mm2和23 200个/mm2, 依然保持着较大的动态范围。室温条件下(20 ℃), 工作在 5 V过偏压的EQR SiPM至少可分辨13个光电子; 15 μm和7 μm EQR SiPM的增益分别为5.1×105和1.1×105, 在400 nm波长下的峰值光探测效率分别达到40%和34%。

Silicon photomultipliers with epitaxial quenching resistors(EQR SiPM) are the bulk resistors under each microcell in the epitaxial layer that are used as the quenching resistors. To enhance the photon detection efficiency and solve the problems of lower fill factor and smaller gain for the large dynamic range of EQR SiPM, Novel Device Laboratory (NDL) has changed the size of microcells and newly developed SiPMs with microcell sizes of 15 μm and 7 μm and an active area of 1 mm×1 mm based on its previous work. By changing the size of the microcell, the filling factor of the device is effectively increased, thus, improving the photon detection and gain efficiency. The microcell densities of the 15 μm and 7 μm devices are 4 400/mm2 and 23 200/mm2, respectively, which still maintain a large dynamic range. EQR SiPMs can distinguish at least 13 p.e. and the gain values are 51×105 and 1.1×105 under 5 V overvoltage. Moreover, the peak photon detection efficiencies at a 400 nm wavelength can reach 40% and 34%.