A solution-processable vanadium oxide film was prepared by sol-gel reaction on a bulk-heterojunction and adopted as the hole collection interlayer of inverted polymer solar cells that were based on a blend of commercial low bandgap polymer and [6,6]-phenyl C-61 butyric acid methyl ester as the photoactive layer. The developed cell shows an efficiency of 6.29% compare to 6.24% efficiency from the normal devices, the thus-prepared inverted devices demonstrated the feasibility of this alternative approach for developing an ease all-solution route for fabricating air-stable device using low-temperature processes in air ambient. (C) 2012 Elsevier B.V. All rights reserved.