Geiger Mode Ge-on-Si Single-Photon Avalanche Diode Detectors

High efficiency single photon avalanche detectors (SPADs) based on the Ge-on-Si material system are a promising emerging technology for high sensitivity optical detection in the short-wave infrared region. Here we demonstrate record single photon detection efficiencies of 38% at 1310nm with an operating temperature of 125K. This was achieved using a novel planar geometry which allowed us to achieve an NEPs of 3×10 ^-16 WHz ^-1/2 and reduced afterpulsing when compared to InGaAs/InP based SPADs operated in nominally identical conditions.