Molybdenum oxide (MoOX) has drawn increasing attention in organic photovoltaic cells due to the large performance enhancement achieved in organic light emitting diodes. In this work, we report on inverted polymer photovoltaics (PVs) with solution-processed MoOX as anodic modification to enhance the performance of PVs. MoO3 is reduced to MoOX with x < 3 after air-plasma treatment and then plays a role more closely to the thermally deposited MoOX, whose oxygen ratio is reduced during high temperature deposition. The reduced oxygen ratio provides more effective transport, thus enhancing theist of the,devices. The PCE of the device with solution-processed MoOX is then enhanced to over 4%, which is comparable to that of thermally deposited MoOX. As a result, this work provides good compatibility for deposition of solution-process MoOX on top of polymer:fullerene blends in inverted polymer PVs to achieve better performance. (C) 2012 Elsevier B.V. All rights reserved.