Photovoltaic organic light-emitting diodes (PVOLEDs) that have dual functions of organic light-emitting diodes and organic solar cells have been studied. Using the structure of glass/ITO anode/hole transporting layer (HTL)/5,6,11,12-tetraphenylnaphthacene (rubrene)/C-60/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/LiF/Al, we examined the dependence of properties for PVOLEDs on HTL materials. Using N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB) with high hole mobility and high lowest-unoccupied molecular orbital (LUMO) level as a HTL material, we obtained the PVOLED that operated as an organic solar cell with 1.86% power conversion efficiency under reverse bias and as an organic light-emitting diode under forward bias with approximately 700 cd/m(2) luminance at 7V.