Strategy to improve photovoltaic performance of DSSC sensitized by using novel nanostructured La dopped TiO2-graphene electrodes

Abstract

A novel series of La/TiO2-graphene (GLT) materials were synthesized, and then used in the production of counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The electrode properties of various CEs were comprehensively analyzed using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction. DSSCs, based on various CEs, were characterized using electrochemical impedance spectroscopy measurements. DSSCs fabricated using the La/TiO2-graphene nanocomposite CEs yielded an efficiency of 6.75%. The La/TiO2-graphene CEs exhibited efficient electrocatalytic capability, because catalytic La particles were uniformly distributed on the surface of graphene. Moreover, we also demonstrated the effect of a thin compact layer in DSSCs by their architecture with various amounts of graphene materials. The results indicated that a DSSC with a La/TiO2-graphene CE can exhibit an efficiency comparable to that of a platinum (Pt) CE DSSC, and can therefore replace conventional Pt CE DSSCs, to lower the cost of solar cells.