a-SiOx films have been prepared using silane and pure oxygen as reactive gases in plasma CVD system. Diborane was introduced as a doping gas to obtain p-type conduction silicon oxide. Infrared absorption spectra show the incorporation of Si-O stretch mode around 1000 cm(-1). The optical bandgap increases with the oxygen to silane gas ratio, while the electrical conductivity decreases. Hydrogenated amorphous silicon solar cells have been fabricated using p-type a-SiOx with around 1.85 eV optical bandgap and conductivity greater than 10(-7) S/cm, The measured current-voltage characteristics of the solar cells under 100 mW/cm(2) artificial light are V-oc = 0.84 V, J(sc) = 14.7 mA/cm(2), FF = 0.635 with a conversion efficiency of 7.84%. (C) 2001 Elsevier Science B.V. All rights reserved.