In this work, we investigate heterojunction emitters deposited by Hot-Wire CVD on p-type crystalline silicon. The emitter structure consists of an n-doped film (20 nm) combined with a thin intrinsic hydrogenated amorphous silicon buffer layer (5 nm). The microstructure of these films has been studied by spectroscopic ellipsometry in the UV-visible range. These measurements reveal that the microstructure of the n-doped film is strongly influenced by the amorphous silicon buffer. The Quasy-Steady-State Photoconductance (QSS-PC) technique allows us to estimate implicit open-circuit voltages near 700 mV for heterojunction emitters on p-type (0.8 ohm-cm) FZ silicon wafers. Finally, 1 cm(2) heterojunction solar cells with 15.4% conversion efficiencies (total area) have been fabricated on flat p-type (14 ohm-cm) CZ silicon wafers with aluminum back-surface-field contact. (c) 2007 Elsevier B.V. All rights reserved.