Crystalline silicon surface passivation by amorphous silicon deposited by three different chemical vapor deposition (CVD) techniques at low (T∼130 °C) temperatures is compared. For all three techniques, surface recombination velocities (SRVs) are reduced by two orders of magnitude after prolonged thermal annealing at 200 °C. This reduction correlates with a decreased dangling bond density at the amorphous-crystalline interface, indicating that dangling bond saturation is the predominant mechanism. All three deposition methods yield excellent surface passivation. For a-Si:H layers deposited by radio frequency plasma enhanced CVD, we obtain outstanding carrier lifetimes of 10.3 ms, corresponding to SRVs below 1.32 cm/s.