Synthesis of ZnO and Fe2O3 nanoparticles by sol–gel method and their application in dye-sensitized solar cells

ZnO and Fe2O3 nanoparticles have been formed in a silica matrix, through the sol–gel method and were used as a photoanode to fabricate dye-sensitized solar cells (DSCs). The obtained oxides were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscope and UV–visible absorption spectroscopy. The results indicate that ZnO and Fe2O3 prepared by this method may be used as photoanodes in photo-electro-chemical energy conversion systems. DSSCs have been built using eosin Y as photosensitizer and their photocurrent, open-circuit voltage, fill factor and efficiency have been measured under direct sunlight illumination (1000 Wcm−2). A ZnO-film solar cell had the best performance with an open-circuit voltage of Voc=0.7 V and short-circuit current density of Isc=490 μA/cm2. This was attributed to high optical gap energy and transparency of ZnO compared to Fe2O3. The effects of annealing temperature and concentration of Fe2O3 on conversion efficiency of the Fe2O3 based solar cell were also studied.