This study evaluated the possibility of utilizing a spray-coating process for inverted organic solar cells (IOSCs). The performance and stability of the IOSCs with zinc oxide (ZnO) as the electron transport layer made by different processes, such as spray-coating, spin-coating and sputtering, were investigated. The IOSCs subjected to the spray-coated ZnO layer showed a power conversion efficiency of 3.17 +/- 0.11% under AM 1.5 simulated illumination and stability (> 80% of its original efficiency after 30 days). The device performance and stability of the IOSCs with the spray-coated ZnO layer was compared with those of spin-coated and sputtering deposited layers. (C) 2011 Elsevier B.V. All rights reserved.