In this study, ZnO particles were grown at different ethanol-water concentrations by using a simple hydrothermal method at 97 degrees C. The changes in structure and morphology of particles were investigated by varying the ethanol concentration. Scanning electron microscope images indicated that ethanol concentration was the main factor affecting the morphology and size of the ZnO particles. X-ray diffractometer pattern showed that crystal structures of the ZnO particles changed with the change in ethanol concentration of the starting solution. Zinc hydroxide phases rather than zinc oxide phases were found in ethanol-rich solutions during hydrothermal synthesis. Photovoltaic properties of the as-synthesized ZnO nanocrystals, as photoanode materials, were tested in dye-sensitized solar cells. Dye-sensitized solar cells were fabricated using a natural black carrot dye, and the performances of these cells were investigated for the electrode materials produced at different ethanol-water concentrations. The best solar energy conversion was obtained with ZnO electrodes fabricated at 100% ethanol concentration.