Cryogenic Ge-on-Si avalanche photodiodes operating at 1550 nm wavelength

We report the first demonstration of Ge-on-Si APD for 1550 nm wavelength photodetection at the cryogenic temperature down to 11 K, with I dark =0.369 μA, R =4.84 A/W and G =1840 at V bias = −20.8 V.