Dye-sensitized solar cells (DSSCs) are established on the semiconductor formed between a photo-sensitized anode and an electrolyte to have the potential of being manufactured with low-cost materials. The DSSCs device usually contains a wide band gap semiconductor nanocrystalline porous electrode which is fabricated on a transparent conducting oxide glass and modified with dye, a Pt counter electrode and an electrolyte solution between the two electrodes. The function of semiconductor porous electrode is quite important because the cell's overall energy conversion efficiency strongly depends on the surface and electronic properties of the electrode. Recently, the porous anatase TiO₂ films in DSSCs have shown better energy conversion efficiency, although several other oxide semiconductors, such as ZnO, have been used to prepare the porous electrode. But, the limited improvement of conversion efficiency by energy loss due to recombination between electrons which are either the oxidized dye molecules or electron-accepting types in the electrolyte during the charge transport process. Consequently, investigation on low-cost, instantly available dyes as efficient sensitizers for DSSCs has been further studied but still remains a scientific challenge. Currently, organic dyes have revealed some significant advantages in the applications of DSSCs, including higher absorption coefficients than that of metal complexes with lower amount of organic dyes, many selections of organic dyes, easy controlled and turned light absorption band as well as easy removed the organic dyes by sinter in air on the semiconductor film. In this work, ZnO nanopowder are produced by the method of microwave-assisted synthesis and operated to be the working electrode in the DSSCs for the principal reason that ZnO is beneficial for enhancing the cell's open-circuit photovoltage with flat band potential higher than TiO₂. Moreover, the dye sensitization is carried out by using the electrodes into a solution of Rose Bengal. In the end, the effects of organic dyes Rose Bengal as the photosensitizers on the numerous photovoltaic parameters of ZnO photoelectrode DSSCs such as open-circuit voltage (V_oc), short-circuit current density (J_sc), fill factor (FF), and energy conversion efficiency (η) will be investigated through the characterization of X-ray powder diffraction and scanning electron microscopy for the structural properties and morphologies of ZnO nanostructures, respectively. 

Acknowledgement

The authors would like to acknowledge the support of the project No. MOST 106-2221-E-272-002.