Ultra-low noise single-photon detector based on Si avalanche photodiode
  We report operation and characterization of a lab-assembled single-photon detector based on commercial silicon avalanche photodiodes (PerkinElmer C30902SH, C30921SH). Dark count rate as low as 5 Hz was achieved by cooling the photodiodes down to -80 C. While afterpulsing increased as the photodiode temperature was decreased, total afterpulse probability did not become significant due to detector's relatively long deadtime in a passively-quenched scheme. We measured photon detection efficiency higher than 50% at 806 nm. 
Yong-Su Kim, Youn-Chang Jeong, Sebastien Sauge, Vadim Makarov, Yoon-Ho   Kim
physics.ins-det quant-ph