Microcrystalline silicon carbide (mu c-SiC:H) thin films in stoichiometric form were deposited from the gas mixture of monomethylsilane (MMS) and hydrogen by Hot-Wire Chemical Vapor Deposition (HWCVD). These films are highly conductive n-type. The optical gap E(04) is about 3.0-3.2 eV. Such mu c-SiC:H window layers were successfully applied in n-side illuminated n-i-p microcrystalline silicon thin film solar cells. By increasing the absorber layer thickness from 1 to 2.5 mu m, the short circuit current density (j(SC)) increases from 23 to 26 mA/cm(2) with Ag back contacts. By applying highly reflective ZnO/Ag back contacts, j(SC) = 29.6 mA/cm(2) and eta = 9.6% were achieved in a cell with a 2-mu m-thick absorber layer. (C) 2011 Elsevier B.V. All rights reserved.