P-type microcrystalline silicon (muc-Si (p)) on n-type crystalline silicon (c-Si(n)) heterojunction solar cells is investigated. Thin boron-doped muc-Si layers are deposited by plasma-enhanced chemical vapor deposition on CZ-Si and the V-oc of muc-Si/c-Si heterojunction solar cells is higher than that produced by a conventional thermal diffusion process. Under the appropriate conditions, the structure of thin muc-Si films on (100), (110), and (111) CZ-Si is ordered, so high V-oc of 0.579 V is achieved for 2 x 2 cm(2) muc-Si/multi-crystalline silicon (mc-Si) solar cells. The epitaxial-like growth is important in the fabrication of high-efficiency muc-Si/mc-Si heterojunction solar cells. (C) 2002 Elsevier Science B.V. All rights reserved.