Effect of Natrium Hydroxide Concentration on the Properties of ZnO Thin Film Nanotubes and the Performance of Dye-sensitized Solar Cell
Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
*Email Address : mohd.yusri@ukm.edu.my
Abstract : The synthesis parameter of thin film photovoltaic materials plays important role on their properties and the performance of DSSC. ZnO thin film nanotubes which serve as a photovoltaic material in DSSC was synthesized via seed mediated hydrothermal technique. The effect of natrium hydroxide (NaOH) precursor concentration at constant hexamethylenetetramine (HMT) surfactant and zinc nitrate [Zn(NO3)2] concentration on the morphology, optical absorption and the performance of the dye-sensitized solar cell (DSSC) utilizing the ZnO samples has been investigated. The samples were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and ultraviolet-visible optical absorption techniques. The DSSC was tested under dark condition and under illumination of 100 mW cm-2 light from tungsten halogen lamp. It was found that the morphology and optical absorption of ZnO nanostructure are significantly affected by the NaOH concentration. The diameter of the ZnO nanotubes decreases as the precursor concentration increases. The device does not show rectification property in dark. The photovoltaic parameters increase with the decrease in the NaOH concentration. The DSSC utilizing ZnO nanotubes synthesized at 0.005 M NaOH performs the JSC, VOC, FF and η of 0.80 mA cm-2, 0.38 V, 0.388 and 0.103%, respectively. The highest performance of that cell is due to the broadest absorption window of 0.005 M sample.
Keywords : DSSC,hydrothermal,NaOH,nanotub