Photocurrent enhancement of nanocrystalline zinc oxide films using low cost dyes

Improvement of dye sensitized solar cell was investigated using methyl-violet dye and nanocrystalline ZnO thin film electrodes. A low cost fabrication method and low cost materials were used to prepare this photocell. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the microstructure and surface properties of dye coated ZnO electrodes. According to the XRD and SEM measurements, nanosize particles were found in ZnO film. Smaller nano-particles enhance the effective surface area; therefore the photo-current. ZnO film coated with methyl-violet dye was measured in electrolyte of KI/I₂ with secondary electrode of platinum. Cell thickness and dye coating time were varied in order to obtain optimum photo-current and photovoltage. Photo-current density around 1.33 mA/cm² was obtained for the ZnO films sensitized with methyl-violet dye.