The SnO/ZnO QDs/SnO2 p-n junction is prepared via a simple route of continuous sputtering process and liquid phase synthesis method. The transparence and photoelectric conversion of these devices are investigated, which exhibits a high transmittance of about similar to 80% and an obvious photoelectric conversion enhancement of about similar to 100 times than that of the unmodified p-n junction, that could be mainly attributed to the ZnO QDs, including the unique band gap could provide an efficient photon-generated carrier route and high quantum yield could increase the photon-generated electron.