  The performance of three types of InGaAs/InP avalanche photodiodes is
investigated for photon counting at 1550 nm in the temperature range of
thermoelectric cooling. The best one yields a dark count probability of $%
2.8\cdot 10^{-5}$ per gate (2.4 ns) at a detection efficiency of 10% and a
temperature of -60C. The afterpulse probability and the timing jitter are also
studied. The results obtained are compared with those of other papers and
applied to the simulation of a quantum key distribution system. An error rate
of 10% would be obtained after 54 kilometers.
