To reduce surface recombination velocity (SRV) at the interface between amorphous Si (a-Si) and crystalline silicon (c-Si), we particularly investigated the treatment of c-Si surface prior to a-Si deposition using decomposed radicals of hydrogen (H(2)) and phosphine (PH(3)). The SRV can be reduced dramatically to 1.6 cm/s only for n-type c-Si, while no such reduction is observed in p-type c-Si. Secondary ion mass spectrometry (SIMS) and the Hall effect measurement actually reveal the existence of phosphorus (P) atoms in c-Si near the surface. (C) 2011 Elsevier B.V. All rights reserved.